What separates a vector quantity from a scalar quantity?

A vector has magnitude and direction; a scalar has magnitude only. Velocity is a vector, while speed is a scalar.

When is the point-object model useful in kinematics?

When an object's size and rotation do not matter for the motion being studied. Its position can then represent the whole object.

When may the constant-acceleration kinematic equations be used?

Only over an interval with constant acceleration. They are not general formulas for changing acceleration.

Why must a velocity statement name or imply a reference frame?

Velocity depends on the observer's frame. The same object can be at rest in one frame and moving in another.

Why can horizontal and vertical projectile motion be analyzed separately?

Perpendicular components evolve independently. With negligible air resistance, gravity changes only the vertical component.

Can an object have zero velocity and nonzero acceleration at one instant?

Yes. At the top of a vertical toss, velocity is momentarily zero while gravitational acceleration still points downward.

A runner completes one lap and returns to the start. How do distance and displacement compare?

The distance is one lap, while the displacement is zero. Displacement depends only on the change from initial to final position.

What makes a reference frame convenient for a motion problem?

It makes the relevant positions or velocities simple. A good frame reduces bookkeeping without changing physical predictions.

How are the components of a launch velocity v at angle θ found?

v_x = v cos θ and v_y = v sin θ. The angle is measured from the positive horizontal axis.

What does average velocity measure?

Displacement per elapsed time. In one dimension, v_avg = Δx/Δt; direction comes from the sign of Δx.

Do a vector's magnitude and its component use different SI units?

No. A vector and each of its components use the same unit; for example, velocity and its x-component both use m/s.

A velocity-versus-time graph curves upward and becomes progressively steeper while staying above zero. What does that show?

The object moves in the positive direction and speeds up with increasing positive acceleration. The graph's slope is acceleration; because that slope changes, the acceleration is nonuniform.

What are a projectile's horizontal and vertical accelerations when air resistance is negligible and up is positive?

a_x = 0 and a_y = -g. Horizontal velocity stays constant while vertical velocity changes.

What does average acceleration measure?

Change in velocity per elapsed time. In one dimension, a_avg = Δv/Δt.

What does a negative one-dimensional vector component mean?

It points opposite the chosen positive direction. The minus sign describes direction, not a negative physical size.

For constant acceleration, what does v = v₀ + at retrieve?

Velocity after elapsed time t. Use it when initial velocity, constant acceleration, and time are known or related.

How are a vector's magnitude and direction reconstructed from perpendicular components v_x and v_y?

v = √(v_x² + v_y²). When v_x ≠ 0, use θ = tan⁻¹(v_y/v_x) and the component signs to choose the quadrant. If v_x = 0 and v_y ≠ 0, the vector points along +y or -y; if both components are zero, its direction is undefined.

At an instant when velocity is nonzero, how do velocity and acceleration signs show whether a one-dimensional object is speeding up?

It speeds up when velocity and acceleration have the same sign. Opposite signs mean speed is decreasing at that instant.

What does the slope of a position-versus-time graph represent?

Velocity. A steeper slope means a larger speed, and the slope's sign gives direction.

Two observers use inertial frames, where an object with zero net force has constant velocity. If the observers move at constant velocity relative to each other, do they agree on an object's acceleration?

Yes, in a Galilean inertial-frame model. Subtracting a constant frame velocity changes velocity but not acceleration. This definition distinguishes an inertial frame from an accelerating, noninertial frame.

A projectile lands at its launch height with negligible air resistance. How do its launch and landing speeds compare?

They are equal. The horizontal component is unchanged, and the vertical component returns with equal magnitude and opposite sign.

A car's velocity changes from -2 m/s to +6 m/s in 2 s. What is its average acceleration?

+4 m/s². Δv = 8 m/s, and 8 m/s ÷ 2 s = 4 m/s².

If the positive axis is reversed, what happens to a one-dimensional vector component and its magnitude?

The component changes sign, while the magnitude stays the same. A coordinate choice changes the signed description, not the physical vector.

For constant acceleration, what does Δx = v₀t + ½at² retrieve?

Displacement over time t. It includes both initial-velocity motion and the displacement added by constant acceleration.

For a horizontal launch from height h in uniform gravity with negligible air resistance, what sets the time to reach the ground?

The vertical drop alone. Starting with v_y = 0, the time follows h = ½gt² and does not depend on horizontal speed.

Why can average speed differ from the magnitude of average velocity?

Average speed uses total distance, while average velocity uses displacement. Reversing direction increases distance without necessarily increasing displacement.

What does the slope of a velocity-versus-time graph represent?

Acceleration. The slope's units are (m/s)/s = m/s².

A passenger walks forward at 2 m/s inside a train moving forward at 18 m/s. What is the passenger's ground velocity?

20 m/s forward. Add the passenger's train-relative velocity to the train's ground velocity.

Does projectile mass affect the ideal trajectory when air resistance is negligible?

No. All projectiles have the same gravitational acceleration, so equal initial conditions give equal trajectories.

Can an object have nonzero velocity and zero acceleration?

Yes. Constant-velocity motion has nonzero velocity while the velocity change, and therefore acceleration, is zero.

A cart starts from rest with constant acceleration. Which graph should be linear if x = x₀ + ½at² applies?

Position x versus t². Its slope is ½a when the initial velocity is zero.

What does signed area under a velocity-versus-time graph represent?

Displacement. Area below the time axis contributes negative displacement.

At the highest point of a projectile's path, what are its vertical velocity and vertical acceleration?

v_y = 0, but a_y = -g. The vertical velocity pauses before reversing; gravity does not switch off.

How can a motion sensor test whether a cart moves at constant velocity?

Record position at equal time intervals and graph position versus time. A straight line with nearly constant slope supports constant velocity.

A car passes a parked observer at 12 m/s. What is the parked observer's velocity in the car's frame?

-12 m/s. In the car's frame, the ground and observer move backward at the car's speed.

Which constant-acceleration equation connects speed and displacement without using time?

v² = v₀² + 2aΔx. Use signed one-dimensional quantities and constant acceleration.

How could video data test the independence of projectile components?

Track x and y at equal times. A linear x-versus-t graph and a quadratic vertical trend support constant horizontal velocity and vertical acceleration.

A velocity-versus-time graph stays below zero but slopes upward toward zero. What is happening?

The object moves in the negative direction while slowing down. Velocity is negative and acceleration is positive.

How can average velocity over a very short interval approximate instantaneous velocity?

Shrink the time interval around the instant. The displacement divided by that short interval approaches the local position–time graph slope.

A walker moves 7 m east, then 3 m west. What is the one-dimensional displacement if east is positive?

+4 m. Add signed displacements: +7 m + (-3 m) = +4 m.

What shape is the path of a projectile with a nonzero horizontal velocity component in a uniform gravitational field when air resistance is negligible?

A parabola. Constant horizontal velocity and constant vertical acceleration produce the curve. A purely vertical launch is the special case: its spatial path is a vertical line.

In a motion diagram with dots at equal time intervals and velocity arrows, what do wider dot spacing and longer arrows show?

Greater speed. Wider spacing means more distance is covered during each equal time interval, while longer velocity arrows represent a larger velocity magnitude. Each arrow points in the direction of motion.

What does signed area under an acceleration-versus-time graph represent?

Change in velocity. Add that signed area to the initial velocity to find the final velocity.

How is one-dimensional relative velocity calculated for two objects A and B?

v_A relative to B = v_A - v_B. Both velocities must be measured in the same frame before subtracting.

When its speed is nonzero, what direction does a projectile's instantaneous velocity point?

Tangent to its path. Its horizontal and vertical velocity components combine to set that direction.

What does choosing a system boundary decide in a mechanics problem?

It decides which objects belong to the system and which forces count as external. Internal interactions occur between objects inside the boundary.

What belongs on a free-body diagram for one chosen object?

Only forces exerted on that object by other objects. Do not draw velocity, acceleration, or forces the chosen object exerts elsewhere.

What assumptions define the ideal-string model used in introductory algebra-based physics?

The string is massless, inextensible, and flexible. It pulls along its length, doesn't stretch, and can redirect around an ideal pulley.

What does translational equilibrium require?

Zero net force. The object may be at rest or move with constant velocity.

In an inertial frame, how does Newton's second law connect force and motion?

ΣF = ma. The net external force on the chosen object or system causes its acceleration; mass sets how strongly the velocity responds.

How do mass and weight differ?

Mass measures inertia in kilograms; weight is gravitational force in newtons. Near a surface, F_g = mg.

AP Physics 1 Flashcards: Complete 8-Unit Course Review

A 400-card AP Physics 1 review of concepts, formulas, graphs, experiments, and reasoning across all eight course units.

Oleh penulis Open Study Contributor

Tentang dek ini

This 400-card deck reviews all eight AP Physics 1 course units: Kinematics; Force and Translational Dynamics; Work, Energy, and Power; Linear Momentum; Torque and Rotational Dynamics; Energy and Momentum of Rotating Systems; Oscillations; and Fluids.

What you'll retrieve

Choose the governing principle for a situation or claim, then explain the prediction in plain language.
Recall what a quantity or equation means, when it applies, how it scales, and which SI unit it uses.
Read slopes, signed areas, extrema, signs, and shapes across motion, force, energy, momentum, rotation, oscillation, and fluid graphs.
Plan a small experiment by naming useful variables, measurements, controls, linearized graphs, slope meanings, and uncertainty checks.
Solve one focused original algebra-based setup with units and a short reason.
Use selected reverse and contrast prompts to recognize conditions and separate common confusion pairs.

The deck does not mechanically reverse every fact. Bare formula-to-symbol lists, long multipart calculations, and imitation exam questions are excluded.

The sequence follows Units 1–8 so motion, forces, energy, and momentum become prerequisites for rotation, orbits, oscillations, and fluids. Definitions appear before dependent uses, while related formula, graph, condition, calculation, and contrast prompts are separated where practical to reduce short-range cueing.

Course scope was checked against the official AP Physics 1 course page. Every prompt, answer, numerical setup, explanation, ordering choice, and metadata field was independently written from common physics knowledge. The CC0 label applies to that original expression and organization to the extent applicable rights exist; it does not claim ownership of physics facts or third-party material.

This is an independently authored, unofficial educational deck. It is not affiliated with, sponsored by, or endorsed by the College Board. AP® is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this product. No AP exam questions, answer keys, scoring guidelines, curriculum text, logos, or trade dress were copied.

Kartu dalam dek ini

Kartu 1
Pertanyaan
What separates a vector quantity from a scalar quantity?
Jawaban
A vector has magnitude and direction; a scalar has magnitude only. Velocity is a vector, while speed is a scalar.
Kartu 2
Pertanyaan
When is the point-object model useful in kinematics?
Jawaban
When an object's size and rotation do not matter for the motion being studied. Its position can then represent the whole object.
Kartu 3
Pertanyaan
When may the constant-acceleration kinematic equations be used?
Jawaban
Only over an interval with constant acceleration. They are not general formulas for changing acceleration.
Kartu 4
Pertanyaan
Why must a velocity statement name or imply a reference frame?
Jawaban
Velocity depends on the observer's frame. The same object can be at rest in one frame and moving in another.
Kartu 5
Pertanyaan
Why can horizontal and vertical projectile motion be analyzed separately?
Jawaban
Perpendicular components evolve independently. With negligible air resistance, gravity changes only the vertical component.
Kartu 6
Pertanyaan
Can an object have zero velocity and nonzero acceleration at one instant?
Jawaban
Yes. At the top of a vertical toss, velocity is momentarily zero while gravitational acceleration still points downward.
Kartu 7
Pertanyaan
A runner completes one lap and returns to the start. How do distance and displacement compare?
Jawaban
The distance is one lap, while the displacement is zero. Displacement depends only on the change from initial to final position.
Kartu 8
Pertanyaan
What makes a reference frame convenient for a motion problem?
Jawaban
It makes the relevant positions or velocities simple. A good frame reduces bookkeeping without changing physical predictions.
Kartu 9
Pertanyaan
How are the components of a launch velocity v at angle θ found?
Jawaban
v_x = v cos θ and v_y = v sin θ. The angle is measured from the positive horizontal axis.
Kartu 10
Pertanyaan
What does average velocity measure?
Jawaban
Displacement per elapsed time. In one dimension, v_avg = Δx/Δt; direction comes from the sign of Δx.
Kartu 11
Pertanyaan
Do a vector's magnitude and its component use different SI units?
Jawaban
No. A vector and each of its components use the same unit; for example, velocity and its x-component both use m/s.
Kartu 12
Pertanyaan
A velocity-versus-time graph curves upward and becomes progressively steeper while staying above zero. What does that show?
Jawaban
The object moves in the positive direction and speeds up with increasing positive acceleration. The graph's slope is acceleration; because that slope changes, the acceleration is nonuniform.
Kartu 13
Pertanyaan
What are a projectile's horizontal and vertical accelerations when air resistance is negligible and up is positive?
Jawaban
a_x = 0 and a_y = -g. Horizontal velocity stays constant while vertical velocity changes.
Kartu 14
Pertanyaan
What does average acceleration measure?
Jawaban
Change in velocity per elapsed time. In one dimension, a_avg = Δv/Δt.
Kartu 15
Pertanyaan
What does a negative one-dimensional vector component mean?
Jawaban
It points opposite the chosen positive direction. The minus sign describes direction, not a negative physical size.
Kartu 16
Pertanyaan
For constant acceleration, what does v = v₀ + at retrieve?
Jawaban
Velocity after elapsed time t. Use it when initial velocity, constant acceleration, and time are known or related.
Kartu 17
Pertanyaan
How are a vector's magnitude and direction reconstructed from perpendicular components v_x and v_y?
Jawaban
v = √(v_x² + v_y²). When v_x ≠ 0, use θ = tan⁻¹(v_y/v_x) and the component signs to choose the quadrant. If v_x = 0 and v_y ≠ 0, the vector points along +y or -y; if both components are zero, its direction is undefined.
Kartu 18
Pertanyaan
At an instant when velocity is nonzero, how do velocity and acceleration signs show whether a one-dimensional object is speeding up?
Jawaban
It speeds up when velocity and acceleration have the same sign. Opposite signs mean speed is decreasing at that instant.
Kartu 19
Pertanyaan
What does the slope of a position-versus-time graph represent?
Jawaban
Velocity. A steeper slope means a larger speed, and the slope's sign gives direction.
Kartu 20
Pertanyaan
Two observers use inertial frames, where an object with zero net force has constant velocity. If the observers move at constant velocity relative to each other, do they agree on an object's acceleration?
Jawaban
Yes, in a Galilean inertial-frame model. Subtracting a constant frame velocity changes velocity but not acceleration. This definition distinguishes an inertial frame from an accelerating, noninertial frame.
Kartu 21
Pertanyaan
A projectile lands at its launch height with negligible air resistance. How do its launch and landing speeds compare?
Jawaban
They are equal. The horizontal component is unchanged, and the vertical component returns with equal magnitude and opposite sign.
Kartu 22
Pertanyaan
A car's velocity changes from -2 m/s to +6 m/s in 2 s. What is its average acceleration?
Jawaban
+4 m/s². Δv = 8 m/s, and 8 m/s ÷ 2 s = 4 m/s².
Kartu 23
Pertanyaan
If the positive axis is reversed, what happens to a one-dimensional vector component and its magnitude?
Jawaban
The component changes sign, while the magnitude stays the same. A coordinate choice changes the signed description, not the physical vector.
Kartu 24
Pertanyaan
For constant acceleration, what does Δx = v₀t + ½at² retrieve?
Jawaban
Displacement over time t. It includes both initial-velocity motion and the displacement added by constant acceleration.
Kartu 25
Pertanyaan
For a horizontal launch from height h in uniform gravity with negligible air resistance, what sets the time to reach the ground?
Jawaban
The vertical drop alone. Starting with v_y = 0, the time follows h = ½gt² and does not depend on horizontal speed.
Kartu 26
Pertanyaan
Why can average speed differ from the magnitude of average velocity?
Jawaban
Average speed uses total distance, while average velocity uses displacement. Reversing direction increases distance without necessarily increasing displacement.
Kartu 27
Pertanyaan
What does the slope of a velocity-versus-time graph represent?
Jawaban
Acceleration. The slope's units are (m/s)/s = m/s².
Kartu 28
Pertanyaan
A passenger walks forward at 2 m/s inside a train moving forward at 18 m/s. What is the passenger's ground velocity?
Jawaban
20 m/s forward. Add the passenger's train-relative velocity to the train's ground velocity.
Kartu 29
Pertanyaan
Does projectile mass affect the ideal trajectory when air resistance is negligible?
Jawaban
No. All projectiles have the same gravitational acceleration, so equal initial conditions give equal trajectories.
Kartu 30
Pertanyaan
Can an object have nonzero velocity and zero acceleration?
Jawaban
Yes. Constant-velocity motion has nonzero velocity while the velocity change, and therefore acceleration, is zero.
Kartu 31
Pertanyaan
A cart starts from rest with constant acceleration. Which graph should be linear if x = x₀ + ½at² applies?
Jawaban
Position x versus t². Its slope is ½a when the initial velocity is zero.
Kartu 32
Pertanyaan
What does signed area under a velocity-versus-time graph represent?
Jawaban
Displacement. Area below the time axis contributes negative displacement.
Kartu 33
Pertanyaan
At the highest point of a projectile's path, what are its vertical velocity and vertical acceleration?
Jawaban
v_y = 0, but a_y = -g. The vertical velocity pauses before reversing; gravity does not switch off.
Kartu 34
Pertanyaan
How can a motion sensor test whether a cart moves at constant velocity?
Jawaban
Record position at equal time intervals and graph position versus time. A straight line with nearly constant slope supports constant velocity.
Kartu 35
Pertanyaan
A car passes a parked observer at 12 m/s. What is the parked observer's velocity in the car's frame?
Jawaban
-12 m/s. In the car's frame, the ground and observer move backward at the car's speed.
Kartu 36
Pertanyaan
Which constant-acceleration equation connects speed and displacement without using time?
Jawaban
v² = v₀² + 2aΔx. Use signed one-dimensional quantities and constant acceleration.
Kartu 37
Pertanyaan
How could video data test the independence of projectile components?
Jawaban
Track x and y at equal times. A linear x-versus-t graph and a quadratic vertical trend support constant horizontal velocity and vertical acceleration.
Kartu 38
Pertanyaan
A velocity-versus-time graph stays below zero but slopes upward toward zero. What is happening?
Jawaban
The object moves in the negative direction while slowing down. Velocity is negative and acceleration is positive.
Kartu 39
Pertanyaan
How can average velocity over a very short interval approximate instantaneous velocity?
Jawaban
Shrink the time interval around the instant. The displacement divided by that short interval approaches the local position–time graph slope.
Kartu 40
Pertanyaan
A walker moves 7 m east, then 3 m west. What is the one-dimensional displacement if east is positive?
Jawaban
+4 m. Add signed displacements: +7 m + (-3 m) = +4 m.
Kartu 41
Pertanyaan
What shape is the path of a projectile with a nonzero horizontal velocity component in a uniform gravitational field when air resistance is negligible?
Jawaban
A parabola. Constant horizontal velocity and constant vertical acceleration produce the curve. A purely vertical launch is the special case: its spatial path is a vertical line.
Kartu 42
Pertanyaan
In a motion diagram with dots at equal time intervals and velocity arrows, what do wider dot spacing and longer arrows show?
Jawaban
Greater speed. Wider spacing means more distance is covered during each equal time interval, while longer velocity arrows represent a larger velocity magnitude. Each arrow points in the direction of motion.
Kartu 43
Pertanyaan
What does signed area under an acceleration-versus-time graph represent?
Jawaban
Change in velocity. Add that signed area to the initial velocity to find the final velocity.
Kartu 44
Pertanyaan
How is one-dimensional relative velocity calculated for two objects A and B?
Jawaban
v_A relative to B = v_A - v_B. Both velocities must be measured in the same frame before subtracting.
Kartu 45
Pertanyaan
When its speed is nonzero, what direction does a projectile's instantaneous velocity point?
Jawaban
Tangent to its path. Its horizontal and vertical velocity components combine to set that direction.
Kartu 46
Pertanyaan
What does choosing a system boundary decide in a mechanics problem?
Jawaban
It decides which objects belong to the system and which forces count as external. Internal interactions occur between objects inside the boundary.
Kartu 47
Pertanyaan
What belongs on a free-body diagram for one chosen object?
Jawaban
Only forces exerted on that object by other objects. Do not draw velocity, acceleration, or forces the chosen object exerts elsewhere.
Kartu 48
Pertanyaan
What assumptions define the ideal-string model used in introductory algebra-based physics?
Jawaban
The string is massless, inextensible, and flexible. It pulls along its length, doesn't stretch, and can redirect around an ideal pulley.
Kartu 49
Pertanyaan
What does translational equilibrium require?
Jawaban
Zero net force. The object may be at rest or move with constant velocity.
Kartu 50
Pertanyaan
In an inertial frame, how does Newton's second law connect force and motion?
Jawaban
ΣF = ma. The net external force on the chosen object or system causes its acceleration; mass sets how strongly the velocity responds.
Kartu 51
Pertanyaan
How do mass and weight differ?
Jawaban
Mass measures inertia in kilograms; weight is gravitational force in newtons. Near a surface, F_g = mg.
Kartu 52
Pertanyaan
How does static friction choose its magnitude before slipping begins?
Jawaban
It matches the needed tangential contact force up to a maximum. In general, f_s ≤ μ_sN.
Kartu 53
Pertanyaan
For an ideal spring in its linear range, what is the spring force when its end is displaced by a signed amount x from the relaxed or natural length?
Jawaban
F_s = -kx. The sign shows that the spring force opposes the signed extension or compression and points toward the relaxed or natural length.
Kartu 54
Pertanyaan
What direction does centripetal acceleration point in circular motion?
Jawaban
Toward the circle's center. It changes the velocity's direction even when speed is constant.
Kartu 55
Pertanyaan
What is the gravitational force magnitude between two point masses?
Jawaban
F_g = Gm₁m₂/r². Here r is the center-to-center separation.
Kartu 56
Pertanyaan
Why isn't the normal force always equal to an object's weight?
Jawaban
It adjusts to the contact and acceleration conditions. Other vertical forces or vertical acceleration can change its magnitude.
Kartu 57
Pertanyaan
What determines a friction coefficient in the simple model?
Jawaban
The pair of contacting materials and their surface condition. It isn't a universal property of either material alone.
Kartu 58
Pertanyaan
What is the centripetal-acceleration magnitude for speed v and radius r?
Jawaban
a_c = v²/r. It is a kinematic requirement, not a separate force.
Kartu 59
Pertanyaan
An elevator accelerates upward. How does the scale reading compare with a rider's weight?
Jawaban
It is greater than the weight. Upward net force requires N - mg > 0.
Kartu 60
Pertanyaan
What does a spring constant k measure, and what is its SI unit?
Jawaban
It measures stiffness in N/m. A larger k means more force is needed for the same displacement in the linear range.
Kartu 61
Pertanyaan
Three equal point masses are at (0,0), (3 m,0), and (0,3 m). Where is their center of mass?
Jawaban
At (1 m,1 m). Average the x-coordinates and y-coordinates separately for equal masses.
Kartu 62
Pertanyaan
What provides centripetal force?
Jawaban
The inward component of real forces such as tension, gravity, friction, or a normal force. 'Centripetal force' names their net inward result.
Kartu 63
Pertanyaan
How is near-surface gravitational field strength related to weight?
Jawaban
F_g = mg. The local field strength g has units N/kg, equivalent to m/s².
Kartu 64
Pertanyaan
How is weight resolved on an incline of angle θ measured from horizontal?
Jawaban
mg sin θ points down the slope and mg cos θ points into the slope. These are components of one gravitational force.
Kartu 65
Pertanyaan
What does Newton's third law say about an interaction between objects A and B?
Jawaban
The force of A on B and the force of B on A have equal magnitude and opposite direction. They act on different objects.
Kartu 66
Pertanyaan
What does signed tangential acceleration describe during circular motion?
Jawaban
It describes how quickly speed changes and which way the tangential acceleration points along the chosen tangent. Its magnitude is the absolute value of the instantaneous rate of change of speed. If it points with the velocity, speed increases; if it points against the velocity, speed decreases. Its sign follows the chosen tangent.
Kartu 67
Pertanyaan
What happens to gravitational force if the separation between two point masses doubles?
Jawaban
It becomes one-fourth as large. The force follows an inverse-square dependence on distance.
Kartu 68
Pertanyaan
How can an adjustable incline estimate a block's coefficient of static friction when no other applied force acts?
Jawaban
Raise the incline slowly until the block just begins to slide. At that threshold, the simple block model gives μ_s = tan θ.
Kartu 69
Pertanyaan
In an inertial frame, what determines the acceleration of a fixed-mass system's center of mass?
Jawaban
The net external force divided by the system's total mass. Internal force pairs cannot change the center-of-mass motion of the whole system.
Kartu 70
Pertanyaan
Which tension components act for a conical pendulum?
Jawaban
The vertical component balances weight, and the horizontal component supplies centripetal force. The bob moves in a horizontal circle.
Kartu 71
Pertanyaan
What does apparent weight measure for an object supported by one surface?
Jawaban
The normal-force magnitude exerted by that support. It can differ from gravitational force when the object accelerates.
Kartu 72
Pertanyaan
How are several forces combined to find net force?
Jawaban
Add them as vectors, component by component. Opposing components subtract according to the chosen signs.
Kartu 73
Pertanyaan
Why is tension uniform along one continuous ideal string?
Jawaban
Every massless segment must have zero net force in the ideal model. Without frictional contact or a massive pulley changing it, the tension magnitude stays the same throughout the string.
Kartu 74
Pertanyaan
A 0.5 kg object moves at 4 m/s in a circle of radius 2 m. What inward net force is required?
Jawaban
4 N. F_in = mv²/r = 0.5 × 16 / 2.
Kartu 75
Pertanyaan
What local equivalence links a uniform gravitational field with a uniformly accelerating reference frame?
Jawaban
A uniform gravitational field and a uniformly accelerating reference frame can produce the same local mechanical effects. Local observations alone may not distinguish them.
Kartu 76
Pertanyaan
For the same net force, what happens to acceleration if mass doubles?
Jawaban
Acceleration is halved. From a = ΣF/m, acceleration is inversely proportional to mass.
Kartu 77
Pertanyaan
How do static and kinetic friction coefficients usually compare for the same pair of surfaces?
Jawaban
Typically μ_s > μ_k. Starting sliding usually requires a larger friction threshold than maintaining it.
Kartu 78
Pertanyaan
How are radial and tangential acceleration combined when circular speed changes?
Jawaban
Add the perpendicular components as vectors. The total magnitude is √(a_c² + a_t²).
Kartu 79
Pertanyaan
A spherically symmetric planet has twice Earth's mass and the same radius. How does its surface g compare with Earth's?
Jawaban
It is twice as large. Surface field strength follows g = GM/R².
Kartu 80
Pertanyaan
Does a force have to point in the direction of motion?
Jawaban
No. A force points in the direction of the interaction; it may speed up, slow down, or turn the object.
Kartu 81
Pertanyaan
Where is the center of mass of a uniform object with a symmetric mass distribution?
Jawaban
At its geometric center of symmetry. Symmetry lets opposite mass elements balance without a detailed sum.
Kartu 82
Pertanyaan
How are speed, period, and frequency related in uniform circular motion?
Jawaban
v = 2πr/T = 2πrf, with T = 1/f. One cycle covers one circumference.
Kartu 83
Pertanyaan
Why is an object apparently weightless in free fall?
Jawaban
Its support force is zero while it and its surroundings accelerate together under gravity. Gravity still acts.
Kartu 84
Pertanyaan
Can forces balance along one axis while an object accelerates along another?
Jawaban
Yes. Zero net force in one component gives zero acceleration only in that direction; another component can remain unbalanced.
Kartu 85
Pertanyaan
Why don't Newton's third-law forces cancel on one object's free-body diagram?
Jawaban
Only one force in the pair acts on that object. The partner force belongs on the other object's diagram.
Kartu 86
Pertanyaan
On a frictionless banked curve, which force components create vertical balance and inward acceleration?
Jawaban
The normal force's vertical component balances weight, while its horizontal component supplies the inward net force.
Kartu 87
Pertanyaan
What motion results when the net force on an object is zero in an inertial frame?
Jawaban
Constant velocity. Rest is the special case with constant velocity equal to zero.
Kartu 88
Pertanyaan
A 3 kg cart has a net horizontal force of 12 N. What is its acceleration?
Jawaban
4 m/s². Use a = ΣF/m = 12/3.
Kartu 89
Pertanyaan
What does the observed equivalence of inertial and gravitational mass imply for free fall?
Jawaban
Free-fall acceleration is independent of the falling object's mass. Inertial and gravitational mass are proportional and conventionally assigned equal numerical values.
Kartu 90
Pertanyaan
Does friction in the simple dry-friction model depend on apparent contact area?
Jawaban
No. For a fixed normal force and the same contacting materials, the model treats friction magnitude as independent of apparent contact area.
Kartu 91
Pertanyaan
When should Hooke's-law predictions be treated cautiously?
Jawaban
When deformation leaves the spring's linear elastic range. Force may no longer be proportional to displacement.
Kartu 92
Pertanyaan
What bank angle θ supports speed v on an ideal frictionless curve of radius r?
Jawaban
tan θ = v²/(rg). The result assumes no vertical acceleration and no friction.
Kartu 93
Pertanyaan
Why do internal forces cancel when finding the net force on a complete system?
Jawaban
They occur in equal-and-opposite pairs between system parts. Each pair sums to zero in the system's force total.
Kartu 94
Pertanyaan
An elevator moves downward at constant speed. How does the scale reading compare with weight?
Jawaban
It equals the weight. Constant velocity means zero acceleration and N - mg = 0.
Kartu 95
Pertanyaan
What assumptions let an ideal pulley redirect a string without changing its tension magnitude?
Jawaban
The pulley is massless and frictionless, and the string is ideal. It changes the tension's direction while the magnitude stays the same on both sides.
Kartu 96
Pertanyaan
What does inertia describe?
Jawaban
An object's resistance to changes in velocity. Mass measures translational inertia.
Kartu 97
Pertanyaan
For the same fixed-mass object or system across all measurements, what does the slope of a net-force-versus-acceleration graph represent?
Jawaban
Its mass. Written as ΣF = ma, the graph has slope m when the object or system and its mass stay fixed.
Kartu 98
Pertanyaan
Does zero net force mean no forces act?
Jawaban
No. Several forces can act and cancel vectorially.
Kartu 99
Pertanyaan
What is the common model for kinetic-friction magnitude?
Jawaban
f_k = μ_kN. It applies while the surfaces slide under the model's assumptions.
Kartu 100
Pertanyaan
How could hanging masses measure the spring constant of one ideal spring?
Jawaban
At static equilibrium, record the spring's extension for several known weights and graph mg versus extension. Keep the same spring in its linear range; the slope is k.
Kartu 101
Pertanyaan
For the same object at the same circular radius, how does required inward net force change if speed doubles?
Jawaban
It becomes four times as large. F_in = mv²/r depends on speed squared.
Kartu 102
Pertanyaan
Where is the center of mass of two point masses on an x-axis?
Jawaban
At x_cm = (m₁x₁ + m₂x₂)/(m₁ + m₂). It lies closer to the larger mass.
Kartu 103
Pertanyaan
Why must net force, rather than one selected force, be used in ΣF = ma?
Jawaban
All external forces contribute to acceleration. Ignoring a force changes the vector sum and the prediction.
Kartu 104
Pertanyaan
Why can tension vary along a hanging chain with nonnegligible mass?
Jawaban
Higher sections must support and accelerate more chain below them. Newton's third law still applies locally to each interaction; it does not make tension uniform everywhere.
Kartu 105
Pertanyaan
What makes a reference frame inertial?
Jawaban
An object with zero net force has constant velocity in that frame. A frame accelerating relative to an inertial frame is noninertial.
Kartu 106
Pertanyaan
How could carts test the proportionality between acceleration and net force?
Jawaban
Keep total mass constant, vary the applied net force, and graph acceleration versus force. A line through the origin supports a ∝ ΣF.
Kartu 107
Pertanyaan
How does Kepler's third-law scaling compare two satellites in circular orbits at center-to-center radii r when their masses are negligible relative to the same fixed central mass?
Jawaban
T² ∝ r³. The circular orbit with the larger center-to-center radius has the longer period.
Kartu 108
Pertanyaan
Which direction does kinetic friction act?
Jawaban
Opposite the relative sliding of the contacting surfaces. It is not automatically opposite the object's velocity in every frame.
Kartu 109
Pertanyaan
What does the slope of a spring-force-versus-displacement graph give?
Jawaban
-k when signed force is graphed against signed displacement. The slope magnitude is the spring constant.
Kartu 110
Pertanyaan
What is the minimum speed at the top of an ideal vertical loop of radius r when gravity alone supplies the inward force?
Jawaban
v_min = √(gr). At the threshold, the support force or tension is zero.
Kartu 111
Pertanyaan
What is translational kinetic energy?
Jawaban
Energy associated with an object's translational motion. For a point-like object, K = ½mv².
Kartu 112
Pertanyaan
How is work by a constant force calculated when its point of application undergoes a straight displacement?
Jawaban
W = Fd cos θ. Here d is the displacement of the force's point of application, and θ is the angle between the force and that displacement.
Kartu 113
Pertanyaan
What does power measure?
Jawaban
The rate of energy transfer or conversion. P_avg = ΔE_transferred/Δt; when work is the relevant transfer, P_avg = W/Δt.
Kartu 114
Pertanyaan
What does conservation of energy say for an isolated system?
Jawaban
The system's total energy stays constant. Energy may change form or move among system parts, but it is not created or destroyed.
Kartu 115
Pertanyaan
Can translational kinetic energy be negative?
Jawaban
No. Mass is positive and speed is squared, so translational kinetic energy is zero or positive.
Kartu 116
Pertanyaan
What does negative work by a force mean?
Jawaban
The force makes a negative contribution to the system's kinetic-energy change. Its component opposes the displacement of its point of application; potential energy may rise while total mechanical energy stays constant.
Kartu 117
Pertanyaan
What is the near-surface change in gravitational potential energy?
Jawaban
ΔU_g = mgΔy. It applies when g can be treated as constant.
Kartu 118
Pertanyaan
When is a chosen system's mechanical energy K + U conserved?
Jawaban
When no net energy crosses the system boundary and no internal process converts energy in either direction between mechanical and nonmechanical forms. If either condition fails, K + U can change even though total energy still balances for the system plus surroundings.
Kartu 119
Pertanyaan
What is the SI unit of power?
Jawaban
The watt, W. One watt equals one joule per second.
Kartu 120
Pertanyaan
For an object modeled as a particle, what connects net work by all forces to its change in translational kinetic energy?
Jawaban
The work–energy theorem: W_net = ΔK. Under the particle model, positive net work raises translational kinetic energy and negative net work lowers it. A rotating rigid system requires total kinetic energy and work at the forces' points of application.
Kartu 121
Pertanyaan
A ball falls from rest through height h near a planet's surface. For the ball–planet system, g is constant and air resistance is negligible. What speed does energy conservation predict?
Jawaban
v = √(2gh). The system's mgh decrease in gravitational potential energy becomes ½mv².
Kartu 122
Pertanyaan
Does choosing a different zero level for potential energy change physical predictions?
Jawaban
No. Only potential-energy differences enter measurable energy changes.
Kartu 123
Pertanyaan
Can an engine do the same work with different average power?
Jawaban
Yes. Doing the same work in less time requires greater average power.
Kartu 124
Pertanyaan
When does a constant nonzero force do zero work over an interval?
Jawaban
When its point of application has zero displacement or its displacement is perpendicular to the force. Then W = Fd cos θ is zero.
Kartu 125
Pertanyaan
A particle-modeled block slides down a fixed frictionless track. Does the path shape affect its final speed at a given lower height?
Jawaban
No. With only gravity doing work, the potential-energy change depends on height, not path.
Kartu 126
Pertanyaan
How does translational kinetic energy change if speed doubles at constant mass?
Jawaban
It becomes four times as large. Kinetic energy depends on v².
Kartu 127
Pertanyaan
What is the elastic potential energy of an ideal spring displaced by a signed amount x from its relaxed or natural length, with U_s = 0 there?
Jawaban
U_s = ½kx². Choosing zero energy at the relaxed length gives the same stored energy for equal-magnitude extension or compression.
Kartu 128
Pertanyaan
What does signed area under a force-component-versus-position graph represent when position tracks that force's point of application?
Jawaban
Work done by that force along the measured coordinate. Area below the position axis counts as negative work under the graph's sign convention.
Kartu 129
Pertanyaan
A chosen system starts with 20 J of mechanical energy and converts 6 J of it into thermal energy, with no energy crossing the boundary. How much mechanical energy remains?
Jawaban
14 J. The 6 J thermal-energy increase matches the mechanical-energy decrease.
Kartu 130
Pertanyaan
What shape does a translational-kinetic-energy-versus-speed graph have for fixed mass?
Jawaban
The right-hand half of an upward-opening parabola through the origin. Speed is nonnegative, and K is proportional to v², not v.
Kartu 131
Pertanyaan
A machine transfers 600 J in 3 s. What is its average power?
Jawaban
200 W. Divide energy transferred by elapsed time.
Kartu 132
Pertanyaan
Why does the normal force do no work on a nonrotating block sliding across a fixed horizontal floor?
Jawaban
The force is perpendicular to the horizontal displacement of its points of application. Their dot product is zero in this pure-translation model.
Kartu 133
Pertanyaan
A coaster modeled as a particle moves on a fixed frictionless track. Where is its speed greatest?
Jawaban
At the lowest accessible position. Gravitational potential energy is smallest there, so kinetic energy is largest.
Kartu 134
Pertanyaan
Two objects have equal mass and velocities of equal magnitude but opposite direction. How do their translational kinetic energies compare?
Jawaban
They are equal. Kinetic energy uses speed and has no direction.
Kartu 135
Pertanyaan
What makes work by a conservative force path independent?
Jawaban
It depends only on the initial and final configurations. Any two paths between the same endpoints give the same conservative-force work.
Kartu 136
Pertanyaan
A 10 N force acts while its point of application moves 3 m in the force direction. How much work does the force do?
Jawaban
30 J. Here θ = 0, so W = Fd = 10×3.
Kartu 137
Pertanyaan
How is total potential energy built for a system with several interacting pairs?
Jawaban
Add the potential energy assigned to each relevant pair. Count each interaction pair once and use one consistent reference choice.
Kartu 138
Pertanyaan
How should external work appear in an energy equation?
Jawaban
As energy transferred across the system boundary. A useful form is ΔE_system = W_external + other transfers.
Kartu 139
Pertanyaan
How does a spring launch problem combine energy forms?
Jawaban
Initial elastic energy becomes kinetic energy and possibly gravitational or thermal energy. Write only the forms present in the chosen initial and final states.
Kartu 140
Pertanyaan
For a constant force parallel to the velocity of its point of application, how is instantaneous mechanical power calculated?
Jawaban
P = Fv. More generally, P = F·v_point, so only the force component along that point's velocity contributes.
Kartu 141
Pertanyaan
How does translational kinetic energy change if mass triples at constant speed?
Jawaban
It triples. Kinetic energy is directly proportional to mass.
Kartu 142
Pertanyaan
How much net work does a conservative force do around a path that returns to the initial configuration?
Jawaban
Zero. The initial and final potential energies are the same.
Kartu 143
Pertanyaan
Where is stable equilibrium on a potential-energy-versus-position graph?
Jawaban
At a local minimum. Small displacements produce forces that point back toward the minimum.
Kartu 144
Pertanyaan
Which displacement belongs in the work done by a force on a rigid object?
Jawaban
The displacement of that force's point of application. Using the center-of-mass displacement can be wrong when the object also rotates.
Kartu 145
Pertanyaan
What happens to mechanical energy when kinetic friction acts inside the chosen system?
Jawaban
Some mechanical energy becomes thermal energy. The broader system's total energy still balances.
Kartu 146
Pertanyaan
A nonrotating particle falls from rest through vertical drop h under constant g. If its gravitational-potential decrease becomes only translational kinetic energy, with no other energy changes, what graph linearizes final speed?
Jawaban
Graph v² versus drop height h. Under those conditions, v² = 2gh, so the slope should be 2g.
Kartu 147
Pertanyaan
If two students start and finish a stair climb at the same speeds, how could data compare their average mechanical output power against gravity?
Jawaban
Measure each student's mass, vertical rise, and climb time, then calculate mgh/t. Equal initial and final speeds make ΔK = 0; if ΔK is negligible, the result is an approximation. This is mechanical output power against gravity, not metabolic input power.
Kartu 148
Pertanyaan
How can force-sensor data measure work when force changes as its point of application moves?
Jawaban
Graph the force component along the motion against the point-of-application position and find the signed area. A rectangle formula isn't enough for a varying force.
Kartu 149
Pertanyaan
Why is potential energy assigned to a system rather than one isolated object?
Jawaban
It belongs to an interaction between system parts. Gravitational potential energy, for example, belongs to the object–Earth system.
Kartu 150
Pertanyaan
How can work by a nonconservative force depend on path?
Jawaban
Different routes can have different force histories or path lengths. Kinetic-friction work, for example, can change with distance traveled.
Kartu 151
Pertanyaan
A 2 kg cart moves at 3 m/s. What is its translational kinetic energy?
Jawaban
9 J. K = ½(2)(3²) = 9 J.
Kartu 152
Pertanyaan
A block slides distance d across a stationary surface while constant kinetic friction f_k opposes its displacement. What work does friction do on the block?
Jawaban
W_f = -f_k d. The negative sign follows from friction pointing opposite the block's displacement in this stated setup.
Kartu 153
Pertanyaan
A 2 kg object rises 5 m where g = 10 m/s². What is ΔU_g?
Jawaban
+100 J. ΔU_g = mgΔy = 2 × 10 × 5.
Kartu 154
Pertanyaan
Why are energy bar charts useful?
Jawaban
They make initial energy, final energy, and transfers explicit. A correct chart respects the chosen system and reference levels.
Kartu 155
Pertanyaan
A motor lifts the same load through the same height twice as fast. Both lifts begin and end at the same speeds and have equal or negligible dissipative losses. How do the motor's mechanical output work and average power compare?
Jawaban
The mechanical output work is unchanged, while average power doubles. The two lifts have the same ΔU_g, the same ΔK, and the same losses, so the same output energy is delivered in half the time.
Kartu 156
Pertanyaan
A nonrotating 1 kg block starts from rest and receives 18 J of net work. What speed does it reach?
Jawaban
6 m/s. For this pure-translation model, ΔK = 18 J = ½(1)v².
Kartu 157
Pertanyaan
Why is gravitational potential energy lower when two attracting point masses—or nonoverlapping spherical bodies—are closer in the inverse-square model?
Jawaban
Energy must be supplied to separate them. With zero chosen at infinite center-to-center separation, U_g = -GMm/r.
Kartu 158
Pertanyaan
What does a steep potential-energy graph imply about force magnitude in one dimension?
Jawaban
A large force magnitude. Force points toward decreasing potential energy and corresponds to the negative slope of U(x).
Kartu 159
Pertanyaan
An ideal spring with k = 80 N/m is compressed 0.50 m from its relaxed length. With U_s = 0 at that length, what elastic energy is stored?
Jawaban
10 J. U_s = ½(80)(0.50²).
Kartu 160
Pertanyaan
A constant 50 N force acts while its point of application moves at 4 m/s in the force direction. What mechanical power is delivered?
Jawaban
200 W. P = Fv_point = 50 × 4.
Kartu 161
Pertanyaan
If potential energy decreases by 30 J and no energy crosses the system boundary, what happens to the other energy forms?
Jawaban
They increase by a total of 30 J. Often kinetic energy rises, but thermal or other forms may share the increase.
Kartu 162
Pertanyaan
Does an object's translational kinetic energy depend on the reference frame?
Jawaban
Yes. Different inertial observers can measure different speeds and therefore different K = ½mv² for the same object.
Kartu 163
Pertanyaan
Why can work depend on the system boundary?
Jawaban
Changing the system can reclassify energy transfer. For example, friction may be external work on one system but internal thermal-energy conversion in a larger system.
Kartu 164
Pertanyaan
A force-component-versus-position graph for the force's point of application forms a triangle of base 4 m and height 6 N above the axis. What work does it show?
Jawaban
12 J. The signed area is ½×4×6.
Kartu 165
Pertanyaan
A motor transfers 50 J into a chosen system while another device transfers 12 J out. What is the net system-energy change?
Jawaban
+38 J. Add the signed transfers across the boundary: 50 J - 12 J.
Kartu 166
Pertanyaan
What is the clearest first step in an energy-conservation problem?
Jawaban
Choose the system and the initial and final states. That choice determines which energies and transfers belong in the equation.
Kartu 167
Pertanyaan
Why can energy methods solve some problems without finding time?
Jawaban
Energy connects states through position, speed, and transfers. Time is absent unless power or a time-dependent process matters.
Kartu 168
Pertanyaan
Why can a force's instantaneous mechanical power be zero while the force is nonzero?
Jawaban
Its point of application may be instantaneously at rest, or the force may be perpendicular to that point's velocity. In either case F·v_point = 0.
Kartu 169
Pertanyaan
What is the SI unit of kinetic energy?
Jawaban
The joule, J. One joule equals 1 kg·m²/s².
Kartu 170
Pertanyaan
How is work by a conservative force related to potential-energy change?
Jawaban
W_conservative = -ΔU. When the conservative force does positive work, potential energy falls.
Kartu 171
Pertanyaan
Where is unstable equilibrium on a potential-energy-versus-position graph?
Jawaban
At a local maximum. A small displacement produces a force that pushes the system farther away.
Kartu 172
Pertanyaan
For a particle moving in a circle at constant speed, does the inward net force change its translational kinetic energy?
Jawaban
No. The inward net force is perpendicular to the particle's instantaneous velocity, so its net work is zero and it changes the velocity's direction rather than its magnitude.
Kartu 173
Pertanyaan
Why should thermal energy not be written as a force?
Jawaban
Thermal energy is an energy store, not an interaction force. Friction is the interaction that converts or transfers energy.
Kartu 174
Pertanyaan
How could a ramp experiment test mechanical-energy conservation for a cart–Earth system when the cart is modeled as a particle?
Jawaban
Measure speed and height at several points, calculate K + U_g with one consistent zero level, and compare within uncertainty. Systematic drift suggests unmodeled energy transfer or conversion.
Kartu 175
Pertanyaan
According to the plotted power's definition and sign convention, what does signed area under a power-versus-time graph represent?
Jawaban
Energy transferred or converted over the interval. Interpret positive and negative areas using the graph's stated sign convention and what its power represents.
Kartu 176
Pertanyaan
What is linear momentum?
Jawaban
p = mv. Momentum is a vector in the direction of velocity and uses SI units kg·m/s.
Kartu 177
Pertanyaan
How is a multi-object system's total momentum found?
Jawaban
Add every object's momentum as a vector. In one dimension, add signed values.
Kartu 178
Pertanyaan
For a chosen object or system, what is external impulse?
Jawaban
The change in its momentum: J_external = Δp. For constant net external force, J_external = F_net,external Δt.
Kartu 179
Pertanyaan
What experimental uncertainty matters strongly when comparing collision kinetic energies?
Jawaban
Velocity uncertainty. Because K depends on v², small speed errors can produce larger relative energy errors.
Kartu 180
Pertanyaan
Why can two objects bounce apart yet still collide inelastically?
Jawaban
Bouncing does not guarantee kinetic-energy conservation. Some kinetic energy becomes internal or thermal energy through deformation, and some may be carried by sound.
Kartu 181
Pertanyaan
A 3 kg cart moves right at 4 m/s. What is its momentum if right is positive?
Jawaban
+12 kg·m/s. p = mv = 3 × 4.
Kartu 182
Pertanyaan
Why can momentum be negative while kinetic energy cannot?
Jawaban
Momentum carries direction through velocity's sign. Kinetic energy depends on speed squared.
Kartu 183
Pertanyaan
When is a system's total linear momentum conserved?
Jawaban
When the net external impulse is zero or negligible during the interval. Internal impulses cancel in the system total.
Kartu 184
Pertanyaan
Two equal masses collide elastically in one dimension; one is initially at rest. What commonly happens?
Jawaban
They exchange velocities. The incoming mass stops and the other leaves with its speed under the ideal conditions.
Kartu 185
Pertanyaan
Can total kinetic energy increase in an explosion?
Jawaban
Yes. Stored internal energy can become kinetic energy. Total momentum is conserved for a defined system with zero or negligible net external impulse, while total energy remains conserved for the system plus surroundings.
Kartu 186
Pertanyaan
How is total momentum related to center-of-mass velocity?
Jawaban
p_total = Mv_cm. M is the system's total mass.
Kartu 187
Pertanyaan
How does a nonzero external impulse affect system momentum?
Jawaban
It changes total momentum by that impulse. J_external = Δp_system.
Kartu 188
Pertanyaan
Two carts start at rest and push apart with negligible external horizontal impulse. How do their final momenta compare?
Jawaban
They are equal in magnitude and opposite in direction. The system began with zero total momentum.
Kartu 189
Pertanyaan
What are equivalent SI units for impulse?
Jawaban
N·s and kg·m/s. Both represent a change in momentum.
Kartu 190
Pertanyaan
What defines an elastic collision?
Jawaban
Both total momentum and total kinetic energy are conserved for the chosen isolated system. Individual objects may exchange both quantities.
Kartu 191
Pertanyaan
How can a force sensor and motion detector test the impulse–momentum theorem for one cart?
Jawaban
Account for every external force component along the measured axis, compare the net-force–time area with m(v_f - v_i), and include uncertainty. Agreement supports J_external = Δp.
Kartu 192
Pertanyaan
A person jumps right from a stationary boat. Neglecting external horizontal impulse, which way does the boat move?
Jawaban
Left. The person and boat acquire opposite momenta so total momentum remains zero.
Kartu 193
Pertanyaan
Why must momentum signs be kept through an impulse calculation?
Jawaban
Impulse changes a vector quantity. Reversal can make Δp larger than either momentum magnitude alone.
Kartu 194
Pertanyaan
What defines a perfectly inelastic collision?
Jawaban
The objects stick together after impact. Momentum is conserved in an isolated system, but kinetic energy decreases as much as the constraints allow.
Kartu 195
Pertanyaan
Why can momentum be conserved during a collision even when large forces act?
Jawaban
For a defined system with zero or negligible net external impulse, the large collision forces are internal. Their equal-and-opposite impulses cancel within that system.
Kartu 196
Pertanyaan
Two objects have equal speed. Which has the larger momentum magnitude?
Jawaban
The object with larger mass. At equal speed, momentum is proportional to mass.
Kartu 197
Pertanyaan
How is momentum conservation written for a two-dimensional isolated interaction?
Jawaban
Conserve components separately: Σp_x,i = Σp_x,f and Σp_y,i = Σp_y,f. Both component equations must hold for the same interaction.
Kartu 198
Pertanyaan
For a chosen object or system, how is average net external force related to impulse?
Jawaban
F_avg,external = Δp/Δt. For the same momentum change, a longer interaction time gives a smaller average force.
Kartu 199
Pertanyaan
Which conservation law alone can determine the shared final velocity of a sticking collision?
Jawaban
Linear momentum conservation, if external impulse is negligible. Kinetic energy is not conserved in the sticking process.
Kartu 200
Pertanyaan
Two equal momentum vectors point along +x and +y. What direction does their total momentum point?
Jawaban
At 45° between the positive axes. Equal perpendicular components produce that resultant direction.
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Kartu 201
Pertanyaan
If external impulse during a collision is small but not zero, what should experimental data show?
Jawaban
Final total momentum should be close to, but not exactly equal to, initial total momentum. The difference estimates external impulse.
Kartu 202
Pertanyaan
A force–time pulse has the same area but twice the peak force and half the duration. How does its impulse change?
Jawaban
It does not change. Impulse depends on total signed area, not peak force alone.
Kartu 203
Pertanyaan
A 1 kg cart at 4 m/s sticks to an identical stationary cart. If external impulse is negligible, how does final kinetic energy compare with the initial 8 J?
Jawaban
It is 4 J, half the initial value. The 4 J decrease in translational kinetic energy becomes internal or thermal energy through deformation, and some energy may be carried by sound.
Kartu 204
Pertanyaan
How can a nearly frictionless cart track improve a momentum-conservation test?
Jawaban
It reduces external horizontal impulse during the collision. That makes the two-cart system closer to isolated.
Kartu 205
Pertanyaan
How does an object's momentum change if its speed doubles at constant mass?
Jawaban
Its momentum magnitude doubles. Momentum depends linearly on speed.
Kartu 206
Pertanyaan
For a chosen object or system, what does signed area under its net-external-force-versus-time graph represent?
Jawaban
External impulse, which equals the change in that object's or system's momentum. Area below the time axis contributes negative impulse under the graph's sign convention.
Kartu 207
Pertanyaan
A firework at rest explodes into two pieces with negligible external impulse. If one piece has twice the mass, how do the piece speeds compare?
Jawaban
The heavier piece moves at half the speed of the lighter piece. Their momentum magnitudes must match.
Kartu 208
Pertanyaan
Why is sticking evidence of an inelastic collision?
Jawaban
The objects share one final velocity, while some translational kinetic energy becomes internal or thermal energy through deformation. Translational kinetic energy is not conserved.
Kartu 209
Pertanyaan
Can a moving two-object system have zero total momentum?
Jawaban
Yes. Equal and opposite momenta cancel even though each object is moving.
Kartu 210
Pertanyaan
A constant 6 N net external force acts on a chosen object for 0.5 s. What impulse does it deliver?
Jawaban
3 N·s in the force direction. Multiply the net external force by the interaction time.
Kartu 211
Pertanyaan
What does a momentum-versus-velocity graph's slope represent for one object?
Jawaban
Its mass. The relationship p = mv is linear through the origin.
Kartu 212
Pertanyaan
A 2 kg cart at +3 m/s sticks to a 1 kg cart at rest. If external horizontal impulse is negligible, what is their final velocity?
Jawaban
+2 m/s. Momentum conservation gives (2×3 + 1×0)/(2+1).
Kartu 213
Pertanyaan
An isolated two-dimensional interaction has known initial total momentum p_total,i and known first outgoing momentum p₁,f. How is the second outgoing momentum found?
Jawaban
Subtract component by component: p₂,f = p_total,i - p₁,f. Thus p₂x,f = p_total,x,i - p₁x,f, with the same subtraction for y.
Kartu 214
Pertanyaan
A 2 kg ball changes velocity from +3 m/s to -1 m/s. What impulse acts on it?
Jawaban
-8 N·s. Δp = m(v_f - v_i) = 2(-1 - 3).
Kartu 215
Pertanyaan
What remains conserved in an isolated inelastic collision?
Jawaban
Total momentum. Some kinetic energy becomes internal or thermal energy through deformation, and some may be carried by sound.
Kartu 216
Pertanyaan
Why does choosing both colliding objects as the system simplify momentum analysis?
Jawaban
Their contact forces become internal. Only external impulse can change the system total.
Kartu 217
Pertanyaan
For a chosen object or system, what does the slope of its momentum-versus-time graph represent?
Jawaban
Net external force. A steeper slope means a larger force in the slope's signed direction.
Kartu 218
Pertanyaan
Why do airbags reduce injury force during a stop?
Jawaban
They increase the stopping time for roughly the same momentum change. That lowers the average force.
Kartu 219
Pertanyaan
A 1 kg cart at 4 m/s sticks to an identical stationary cart. If external impulse is negligible, what final speed do they share?
Jawaban
2 m/s. Momentum 4 kg·m/s is shared by 2 kg.
Kartu 220
Pertanyaan
For a defined collision system with zero or negligible net external impulse, how can before-and-after velocity measurements classify the collision?
Jawaban
First verify total momentum within uncertainty, then compare total kinetic energy. Unchanged kinetic energy supports elastic behavior; any change beyond uncertainty means the collision isn't elastic, with a decrease indicating an ordinary inelastic collision.
Kartu 221
Pertanyaan
What is angular displacement?
Jawaban
The signed angle through which a rigid body rotates. In calculations, radians make the linear–angular relationships direct.
Kartu 222
Pertanyaan
For a rigid body rotating about a chosen fixed axis, what does angular velocity measure?
Jawaban
Signed angular displacement per time about that axis. Average angular velocity is ω_avg = Δθ/Δt under one sign convention.
Kartu 223
Pertanyaan
For a rigid body rotating about a chosen fixed axis, what does angular acceleration measure?
Jawaban
Change in signed angular velocity per time about that axis. Average angular acceleration is α_avg = Δω/Δt.
Kartu 224
Pertanyaan
What does rotational inertia measure?
Jawaban
Resistance to angular acceleration about a specified axis. It depends on mass and how that mass is distributed relative to the axis.
Kartu 225
Pertanyaan
What is the lever arm in a torque calculation?
Jawaban
The perpendicular distance from the axis to the force's line of action. It is not always the full distance to the contact point.
Kartu 226
Pertanyaan
For a planar rigid object in an inertial frame, what two conditions give simultaneous translational and rotational equilibrium?
Jawaban
ΣF_external = 0 and Στ_external = 0 about a fixed axis. Static equilibrium also requires the object to be at rest.
Kartu 227
Pertanyaan
Two points lie on the same rotating rigid disk. Which rotational quantities are the same?
Jawaban
They share angular displacement, angular velocity, and angular acceleration. Their linear speeds and accelerations can differ with radius.
Kartu 228
Pertanyaan
How is rotational inertia found for a collection of point masses?
Jawaban
I_total = Σmᵢrᵢ². Each rᵢ is that mass's perpendicular distance from the chosen axis.
Kartu 229
Pertanyaan
What determines the magnitude of torque from one force about a chosen axis?
Jawaban
τ = rF sin θ = r_perp F. The radius vector r runs from the axis to the force's point of application, θ is the angle between r and the force, and r_perp is the lever arm.
Kartu 230
Pertanyaan
What is Newton's second law for a rigid system rotating about an axis fixed in an inertial frame?
Jawaban
Στ_external = Iα when rotational inertia I about that axis is constant. Net external torque and angular acceleration use the same signed-axis convention.
Kartu 231
Pertanyaan
For a point on a rigid body rotating about a fixed axis, how is signed arc displacement related to signed angular displacement in radians?
Jawaban
Δs = rΔθ. Here r is the point's perpendicular distance from the fixed axis, and both displacements use matching sign conventions along the circular path.
Kartu 232
Pertanyaan
In a planar rigid-body model, can an object with zero net external force and zero net external torque about its center of mass be moving?
Jawaban
Yes. Its center of mass may translate at constant velocity while it rotates at constant angular velocity; the stated zero net force and center-of-mass torque don't require rest.
Kartu 233
Pertanyaan
At an instant when ω ≠ 0, what do the signs of angular velocity and angular acceleration show about rotational speed?
Jawaban
Matching signs mean the rotation speeds up; opposite signs mean it slows down. The sign convention chooses which rotation direction is positive.
Kartu 234
Pertanyaan
How are clockwise and counterclockwise torques combined?
Jawaban
Choose one direction as positive and add signed torques. Net torque is the algebraic sum about the same axis.
Kartu 235
Pertanyaan
For the same rigid system with constant rotational inertia about the same axis fixed in an inertial frame, what happens if net-external-torque magnitude doubles?
Jawaban
Angular-acceleration magnitude doubles. Under those conditions, |α| is directly proportional to |Στ_external|.
Kartu 236
Pertanyaan
Why must an axis be named when stating rotational inertia?
Jawaban
The same object has different rotational inertia about different axes. Mass distribution relative to the chosen axis changes.
Kartu 237
Pertanyaan
For one rigid body rotating about a fixed axis, what does the slope of its angular-position-versus-time graph represent?
Jawaban
Signed angular velocity about that axis. A constant slope means constant angular velocity under the graph's sign convention.
Kartu 238
Pertanyaan
Why is torque's unit N·m not called a joule?
Jawaban
Torque and energy are different physical quantities despite matching unit dimensions. Torque describes rotational effectiveness of a force.
Kartu 239
Pertanyaan
A rigid wheel has constant I = 2 kg·m² about an axis fixed in an inertial frame and net external torque 8 N·m about that axis. What is its angular-acceleration magnitude?
Jawaban
4 rad/s². |α| = |Στ_external|/I = 8/2.
Kartu 240
Pertanyaan
Where can the weight of a rigid object be treated as acting in a uniform gravitational field?
Jawaban
At the object's center of mass. That single force gives the same net gravitational force and torque.
Kartu 241
Pertanyaan
For a point on a rigid body rotating about a fixed axis, how is tangential-speed magnitude related to angular velocity?
Jawaban
v_t = r|ω|. Here r is the perpendicular distance from the fixed axis. Points farther from the axis move faster even though the rigid body has one angular velocity.
Kartu 242
Pertanyaan
For constant angular acceleration about one fixed axis, what does ω = ω₀ + αt retrieve?
Jawaban
Angular velocity after elapsed time t. Use signed angular quantities about that axis over an interval with constant α.
Kartu 243
Pertanyaan
A free-body diagram for a rigid bar must support a torque calculation about a marked axis. What must it show besides each force's direction and magnitude?
Jawaban
Each force's point of application or line of action relative to the axis. That geometry sets the lever arm and torque sign; omitting it can preserve the net-force picture while losing the net torque.
Kartu 244
Pertanyaan
For the same rigid system about the same axis fixed in an inertial frame, what does the slope of a net-external-torque-versus-angular-acceleration graph represent?
Jawaban
Its constant rotational inertia I about that axis. The graph follows Στ_external = Iα.
Kartu 245
Pertanyaan
A thin hoop and solid disk have the same mass and radius and rotate about their central symmetry axes. With I_hoop = MR² and I_disk = ½MR², which has larger I?
Jawaban
The hoop. More of its mass lies far from the axis.
Kartu 246
Pertanyaan
Why can a rigid object have zero net external force but nonzero net external torque?
Jawaban
External forces can cancel as vectors while acting along different lines. The resulting couple can still change the object's rotation.
Kartu 247
Pertanyaan
Which constant-angular-acceleration equation connects angular velocity and angular displacement about one fixed axis without time?
Jawaban
ω² = ω₀² + 2αΔθ. Use signed quantities about that axis over an interval with constant α.
Kartu 248
Pertanyaan
A 10 N perpendicular force acts 0.40 m from a pivot. What torque magnitude does it produce?
Jawaban
4 N·m. τ = rF for a perpendicular force.
Kartu 249
Pertanyaan
For a rigid body rotating about a fixed axis, how is the signed tangential-acceleration component related to angular acceleration?
Jawaban
For a positive tangent consistent with the angular sign convention, a_t = rα. Its alignment or opposition with velocity determines whether speed increases or decreases.
Kartu 250
Pertanyaan
Why can two equal-mass rigid wheels have different angular-acceleration magnitudes under equal net-external-torque magnitudes about comparable axes fixed in an inertial frame?
Jawaban
Their rotational inertias about those axes can differ because their mass distributions differ. Mass alone doesn't set rotational response.
Kartu 251
Pertanyaan
For one rigid body rotating about a fixed axis, what does signed area under its angular-velocity-versus-time graph represent?
Jawaban
Signed angular displacement about that axis. Area below the time axis contributes negative angular displacement under the graph's sign convention.
Kartu 252
Pertanyaan
A rigid object rests on a support that is slowly tilted in uniform gravity. If gravity and support contact are its only external interactions, sufficient static friction prevents slipping, and the motion is quasistatic, what marks the onset of tipping?
Jawaban
The object's center-of-mass vertical line reaches the edge of its support region. Beyond that point, gravity produces an unbalanced tipping torque.
Kartu 253
Pertanyaan
A point is twice as far from a rigid wheel's fixed axis as another point. How do their tangential speeds compare?
Jawaban
The farther point moves twice as fast. v_t is proportional to radius for their common angular-speed magnitude |ω|.
Kartu 254
Pertanyaan
Does moving the chosen pivot change an individual force's torque?
Jawaban
Yes. Torque depends on the axis, though a correctly solved physical prediction stays consistent.
Kartu 255
Pertanyaan
How does the parallel-axis theorem relate rotational inertia to a parallel axis a distance d from the center of mass?
Jawaban
I = I_cm + Md². Shifting the axis away from the center of mass increases rotational inertia.
Kartu 256
Pertanyaan
How could an experiment determine a rigid wheel's constant rotational inertia about an axis fixed in an inertial frame?
Jawaban
Apply several known signed net external torques about that axis, measure signed angular acceleration, and graph torque versus α. The slope is I.
Kartu 257
Pertanyaan
For a point at perpendicular distance r > 0 from a rigid body's fixed rotation axis, what is the radial-acceleration magnitude?
Jawaban
a_r = v_t²/r = rω². The acceleration points toward the axis. At r = 0, use a_r = rω² = 0; the quotient form isn't defined there.
Kartu 258
Pertanyaan
How could a meterstick experiment test torque balance?
Jawaban
Hang known forces at measured lever arms and compare signed r_perp F values at equilibrium. Repeat with different pivot choices.
Kartu 259
Pertanyaan
For uniform rotation at frequency f, what is the angular-speed magnitude?
Jawaban
|ω| = 2πf. One revolution is 2π rad, and uniform rotation has the same angular-speed magnitude throughout the cycle.
Kartu 260
Pertanyaan
Why is choosing the pivot at an unknown support force often useful?
Jawaban
That force then has zero lever arm and drops out of the torque equation. The physical equilibrium does not depend on the calculation shortcut.
Kartu 261
Pertanyaan
Among parallel axes through or near a rigid object, which gives the minimum rotational inertia?
Jawaban
The parallel axis through the center of mass. Any offset adds the positive term Md².
Kartu 262
Pertanyaan
Compare rigid systems with constant rotational inertia about comparable axes fixed in an inertial frame. If net external torque is the same but I triples, what happens to angular acceleration?
Jawaban
It becomes one-third as large. For each stated system, α = Στ_external/I.
Kartu 263
Pertanyaan
A rigid wheel of radius 0.50 m has angular-speed magnitude 6 rad/s about its fixed axis. What is the rim speed?
Jawaban
3 m/s. v_t = r|ω| = 0.50 × 6.
Kartu 264
Pertanyaan
A 30 N child sits 2 m left of a seesaw pivot. If the seesaw's own weight acts through the pivot, where should a 20 N child sit on the right for balance?
Jawaban
3 m from the pivot. Balance torque magnitudes: 30×2 = 20×r.
Kartu 265
Pertanyaan
For constant angular acceleration about one fixed axis, what does Δθ = ω₀t + ½αt² retrieve?
Jawaban
Angular displacement over elapsed time t. Use signed angular quantities about that axis; the equation combines the initial angular-velocity contribution with the change caused by constant α.
Kartu 266
Pertanyaan
A 20 N force acts at 30° to a radius vector of magnitude 0.60 m from a chosen axis. What torque magnitude results?
Jawaban
6 N·m. |τ| = rF sin θ = 0.60 × 20 × sin 30°.
Kartu 267
Pertanyaan
How does moving mass farther from a rotation axis affect rotational inertia?
Jawaban
It increases rotational inertia strongly. For a point mass, I = mr².
Kartu 268
Pertanyaan
How can angular-acceleration data compare two rigid objects' constant rotational inertias about comparable axes fixed in an inertial frame?
Jawaban
Apply the same measured net-external-torque magnitude about each axis and compare |α|. The object with smaller angular-acceleration magnitude has larger I.
Kartu 269
Pertanyaan
Why must angular displacement be in radians for Δs = rΔθ?
Jawaban
Radians define angle as arc length divided by radius. Degree measure would require a conversion factor.
Kartu 270
Pertanyaan
When does a nonzero force produce zero torque about an axis?
Jawaban
When its line of action passes through the axis. The lever arm is then zero.
Kartu 271
Pertanyaan
What is angular momentum for a rigid object rotating about an axis fixed in an inertial frame?
Jawaban
L = Iω about that axis. Use one signed-axis convention consistently for L and ω.
Kartu 272
Pertanyaan
What magnitude relation holds for a planar, constant-radius rigid object whose center of mass lies on its rolling axis when it rolls without slipping on a stationary surface?
Jawaban
v_cm = R|ω|. Here R is the constant rolling radius; the contact point is instantaneously at rest relative to the surface.
Kartu 273
Pertanyaan
For a rigid system rotating about an axis fixed in an inertial frame, how is work by a constant torque about that axis related to angular displacement?
Jawaban
W = τΔθ when torque and angular displacement use the same signed axis. The angle must be in radians.
Kartu 274
Pertanyaan
For point masses—or nonoverlapping spherical bodies—M and m separated center to center by r, what is gravitational potential energy with zero at infinity?
Jawaban
U_g = -GMm/r. The negative sign reflects U_g = 0 at infinity and attraction. In an isolated gravity-only inverse-square system, total mechanical energy determines binding: E < 0 is bound, while E ≥ 0 is unbound.
Kartu 275
Pertanyaan
When is a chosen system's angular momentum about an axis fixed in an inertial frame conserved?
Jawaban
When net external torque on the system about that axis is zero or negligible over the interval. Internal torques cannot change the system total.
Kartu 276
Pertanyaan
What does kinetic friction do to mechanical energy while a wheel slips on a stationary surface?
Jawaban
It converts mechanical energy into internal or thermal energy while the surfaces slide. Use qualitative energy accounting here; no no-slip relation connects the magnitudes v_cm and R|ω| during the slip.
Kartu 277
Pertanyaan
What is the angular-momentum magnitude of a translating point object about a chosen fixed point in an inertial frame?
Jawaban
L = mvr sin θ = r_perp mv. Here r points from the chosen point to the object, v is its speed, and θ is the angle between them. The SI unit is kg·m²/s.
Kartu 278
Pertanyaan
For a satellite of negligible mass relative to a fixed central body, how do speed and energy change along one gravity-only elliptical orbit?
Jawaban
Speed and kinetic energy are greatest near the central body, while gravitational potential energy is greatest farther away. Total mechanical energy stays constant.
Kartu 279
Pertanyaan
What is a rigid body's rotational kinetic energy about a fixed axis?
Jawaban
K_rot = ½Iω². It depends on rotational inertia about that axis and angular speed.
Kartu 280
Pertanyaan
Two planar rigid objects with constant rolling radii and centers of mass on their rolling axes are released from rest on the same fixed incline. Each rolls without slipping under gravity and its contact forces, with no other applied force or torque and negligible dissipation. Which accelerates faster: the one with smaller or larger I_cm/(MR²)?
Jawaban
The one with smaller I_cm/(MR²). Here I_cm is rotational inertia about the center of mass, M is total mass, and R is that object's constant rolling radius. Under the stated model, a_cm = g sin θ/(1 + I_cm/(MR²)).
Kartu 281
Pertanyaan
How could a rotating-platform experiment test angular-momentum conservation about the platform's axis, treated as fixed in the lab's inertial frame?
Jawaban
Choose the platform, rider, and moved masses as one system. In both the initial and final arrangements, wait until the rider and moved masses are stationary relative to the platform and the whole system co-rotates with one common signed angular velocity; then measure I_i, ω_i, I_f, and ω_f and compare I_iω_i with I_fω_f. Keep net external torque about the axis negligible, reduce bearing friction, and include uncertainty.
Kartu 282
Pertanyaan
For a satellite of mass m negligible beside a fixed central mass M, how are K, U_g, and total mechanical energy E related in a gravity-only circular orbit at center-to-center radius r?
Jawaban
K = -U_g/2 and E = U_g/2 = -K. Since U_g = -GMm/r, this gives K = GMm/(2r) and E = -GMm/(2r).
Kartu 283
Pertanyaan
For a rigid system rotating about an axis fixed in an inertial frame, how is instantaneous mechanical power delivered by a torque about that axis related to angular velocity?
Jawaban
P = τω for signed torque and angular velocity about the same axis. It is the rotational counterpart of P = F·v_point.
Kartu 284
Pertanyaan
In a planar common-axis rigid-body model, what kinetic-energy expression applies to a body rolling without slipping, with I_cm and ω taken about the same axis through its center of mass?
Jawaban
K = ½Mv_cm² + ½I_cmω². In this model, the rigid body's motion combines center-of-mass translation with rotation about one axis through the center of mass. I_cm and ω must refer to that same axis.
Kartu 285
Pertanyaan
Does angular-momentum conservation require rotational kinetic-energy conservation?
Jawaban
No. Internal work can change rotational kinetic energy while angular momentum stays constant.
Kartu 286
Pertanyaan
Why do astronauts feel weightless in orbit even though gravity acts on them?
Jawaban
They and their spacecraft are in continuous free fall together. Apparent weight is small because support forces are small.
Kartu 287
Pertanyaan
Two wheels spin at the same angular speed. Which has more rotational kinetic energy?
Jawaban
The wheel with larger rotational inertia. At common ω, K_rot is proportional to I.
Kartu 288
Pertanyaan
For a chosen system, what does the slope of its angular-momentum-versus-time graph about an axis fixed in an inertial frame represent?
Jawaban
Net external torque on the system about that axis. A constant slope means constant signed net external torque there.
Kartu 289
Pertanyaan
A motor supplies 12 N·m of torque about a shaft axis fixed in the lab's inertial frame while the shaft turns in the torque direction at 10 rad/s. What mechanical power does it deliver?
Jawaban
120 W. Using signed quantities about the shaft axis, P = τω = 12×10.
Kartu 290
Pertanyaan
While a rigid wheel is slipping on a stationary surface, how are the magnitudes v_cm and R|ω| related?
Jawaban
No no-slip equality applies. Their values evolve separately until friction may bring the contact point to rest relative to the surface.
Kartu 291
Pertanyaan
A launched object has negligible mass relative to a fixed central mass M and starts at center-to-center radius r. What minimum speed lets it escape under gravity alone without further propulsion or drag?
Jawaban
v_escape = √(2GM/r). At that threshold, total mechanical energy is zero with the object reaching infinity at zero speed.
Kartu 292
Pertanyaan
In a planar common-axis rigid-body model, what kinetic-energy forms can a rigid body have when it translates and rotates about an axis through its center of mass?
Jawaban
Both translational and rotational kinetic energy. The total is K = ½Mv_cm² + ½I_cmω², where I_cm and ω refer to the same axis through the center of mass.
Kartu 293
Pertanyaan
For a chosen object or system, what is angular impulse about an axis fixed in an inertial frame?
Jawaban
The change in that object or system's angular momentum about the axis. For constant net external torque, ΔL = τ_net,external Δt. Use the same axis and sign convention throughout. Angular impulse has units N·m·s, equivalent to kg·m²/s.
Kartu 294
Pertanyaan
Two equal-mass planar rigid objects have constant rolling radii and centers of mass on their rolling axes. They start from rest at the same height and roll without slipping to the same lower endpoint with negligible dissipation. Why can their final speeds differ?
Jawaban
Their rotational inertias divide the same decrease in gravitational potential energy differently between translation and rotation. A larger I_cm/(MR²) leaves less energy for translational speed, where I_cm is rotational inertia about the center of mass and R is rolling radius.
Kartu 295
Pertanyaan
For a satellite of negligible mass relative to a fixed central body, how does angular momentum behave along one gravity-only elliptical orbit?
Jawaban
It stays constant because gravity exerts zero torque about the central body. The satellite moves faster when closer and slower when farther away.
Kartu 296
Pertanyaan
How does rotational kinetic energy change if angular speed doubles at fixed I?
Jawaban
It becomes four times as large. Rotational kinetic energy depends on ω².
Kartu 297
Pertanyaan
Why should external torque be evaluated about the same axis used for angular momentum?
Jawaban
Both quantities depend on the chosen axis. Mixing axes breaks the conservation statement.
Kartu 298
Pertanyaan
For a chosen object or system about an axis fixed in an inertial frame, what does signed area under its net-external-torque-versus-time graph represent?
Jawaban
Angular impulse, equal to that object or system's ΔL about the axis. Use the graph's signed-axis convention. The area has units N·m·s, equivalent to kg·m²/s.
Kartu 299
Pertanyaan
Why can static friction act on a rigid object rolling without slipping on a stationary rigid surface without necessarily dissipating mechanical energy?
Jawaban
The contact point is instantaneously at rest relative to the surface, so there is no sliding. Static friction can still supply the torque needed for rolling.
Kartu 300
Pertanyaan
For a satellite whose mass is negligible beside a fixed central mass M, what is its speed in a gravity-only circular orbit at center-to-center radius r?
Jawaban
v = √(GM/r). Gravity supplies the inward net force.
Kartu 301
Pertanyaan
A chosen system's included mass co-rotates with one common angular velocity before and after a change. If its rotational inertia about an axis fixed in an inertial frame doubles while net external torque about that axis is negligible, what happens to its angular speed?
Jawaban
It halves. Because all included mass shares one angular velocity in each state, L = Iω applies. With the same axis and sign convention, angular-momentum conservation gives I_iω_i = I_fω_f.
Kartu 302
Pertanyaan
For a rigid system rotating about an axis fixed in an inertial frame, what does signed area under its net-external-torque-versus-angular-position graph represent when angle is in radians?
Jawaban
Net rotational work, equal to the system's change in rotational kinetic energy. Torque and angular position must use the same signed axis.
Kartu 303
Pertanyaan
Why can't the rolling condition alone prove that friction points uphill or downhill?
Jawaban
Friction direction depends on the tendency to slip and the applied forces or torques. Solve the dynamics instead of guessing from motion.
Kartu 304
Pertanyaan
A satellite of mass m, negligible beside a fixed central mass M, follows a circular orbit at center-to-center radius r under gravity alone. What is its total mechanical energy?
Jawaban
E = -GMm/(2r). A larger circular orbit has greater, less-negative energy even though its speed is lower.
Kartu 305
Pertanyaan
A spinning student pulls masses closer to an axis fixed in the lab's inertial frame while net external torque about that axis is negligible. Why does angular speed increase?
Jawaban
Rotational inertia decreases while angular momentum stays constant. Therefore Iω remains constant by increasing ω.
Kartu 306
Pertanyaan
What makes simple harmonic motion a special kind of periodic motion?
Jawaban
Its restoring force or torque is proportional to displacement and points toward equilibrium. Periodic motion alone does not guarantee this relationship.
Kartu 307
Pertanyaan
What does the amplitude of an SHM displacement graph represent?
Jawaban
The maximum distance from equilibrium. It is nonnegative even though displacement alternates sign.
Kartu 308
Pertanyaan
How are period and frequency related?
Jawaban
T = 1/f. Period is seconds per cycle; frequency is cycles per second, measured in hertz.
Kartu 309
Pertanyaan
What is the period of a mass m on an ideal spring of constant k when spring mass and damping are negligible?
Jawaban
T = 2π√(m/k). The motion must stay in the spring's linear SHM range.
Kartu 310
Pertanyaan
For one-dimensional SHM, what is the equilibrium position?
Jawaban
The position where the restoring force or torque—and therefore acceleration along the SHM coordinate—is zero. A stable equilibrium produces a restoring response after a small displacement.
Kartu 311
Pertanyaan
How far apart in phase are displacement and velocity in SHM?
Jawaban
One-quarter cycle. Velocity reaches an extremum when displacement crosses zero.
Kartu 312
Pertanyaan
When can a simple pendulum be modeled as SHM?
Jawaban
For small angular displacements. Then the restoring torque is approximately proportional to angular displacement.
Kartu 313
Pertanyaan
An oscillator completes 12 cycles in 6 s. What are its frequency and period?
Jawaban
f = 2 Hz and T = 0.5 s. Frequency is cycles per time, and period is its reciprocal.
Kartu 314
Pertanyaan
For a horizontal ideal spring oscillator, what is potential energy at displacement x from its relaxed equilibrium length when U_s = 0 there?
Jawaban
U_s = ½kx². It has the same value at +x and -x.
Kartu 315
Pertanyaan
At the equilibrium position of SHM, is the oscillator necessarily at rest?
Jawaban
No. The restoring force or torque and acceleration along the SHM coordinate are zero there, but speed is usually greatest.
Kartu 316
Pertanyaan
How does a spring oscillator's period change if k becomes four times as large?
Jawaban
The period is halved. T is proportional to 1/√k.
Kartu 317
Pertanyaan
How are acceleration and displacement related along the SHM coordinate?
Jawaban
a = -ω²x, where ω = 2πf is the oscillation's angular frequency. Here ω describes the oscillator's phase rate, not a rigid body's rotational angular velocity. The acceleration component along the SHM coordinate points toward equilibrium.
Kartu 318
Pertanyaan
For a horizontal ideal spring oscillator with amplitude A, what is total mechanical energy when U_s = 0 at the relaxed equilibrium length?
Jawaban
E = ½kA². It stays constant when dissipative effects are negligible.
Kartu 319
Pertanyaan
In a small-angle pendulum, where are speed and gravitational potential energy greatest?
Jawaban
Speed is greatest at the bottom; gravitational potential energy is greatest at the turning points. Energy trades between those forms.
Kartu 320
Pertanyaan
How can frequency be read from an oscillation-versus-time graph?
Jawaban
Measure the time between repeating equivalent points to find T, then use f = 1/T. Adjacent peaks are one period apart.
Kartu 321
Pertanyaan
Why does an ideal mass–spring oscillator exhibit SHM?
Jawaban
Its net restoring force is F_net = -kx, where x is displacement from equilibrium. The force is proportional to displacement and points back toward equilibrium.
Kartu 322
Pertanyaan
A horizontal ideal spring has k = 50 N/m and amplitude 0.20 m. With U_s = 0 at equilibrium, what is the oscillator's total energy?
Jawaban
1 J. E = ½(50)(0.20²).
Kartu 323
Pertanyaan
At maximum positive displacement in SHM, what are velocity and acceleration?
Jawaban
Velocity is zero; acceleration has maximum magnitude toward equilibrium. With positive displacement, acceleration is negative.
Kartu 324
Pertanyaan
How does a spring oscillator's period change if its mass becomes four times as large?
Jawaban
The period doubles. T is proportional to √m.
Kartu 325
Pertanyaan
Why isn't uniform circular motion itself one-dimensional SHM?
Jawaban
The object travels around a circle, not back and forth along one line. Its projection onto a diameter does follow SHM.
Kartu 326
Pertanyaan
For the same ideal oscillator, how does total SHM energy change if amplitude doubles while k or mω² stays fixed?
Jawaban
It becomes four times as large. Under those fixed system parameters, total energy is proportional to A².
Kartu 327
Pertanyaan
In one-dimensional SHM, what are speed and acceleration along the SHM coordinate at equilibrium?
Jawaban
Speed is maximum, while acceleration along the SHM coordinate is zero. The restoring force or torque vanishes there.
Kartu 328
Pertanyaan
Does changing amplitude change the period of an ideal spring oscillator or small-angle pendulum?
Jawaban
No within the ideal SHM model. The period depends on system parameters, not amplitude.
Kartu 329
Pertanyaan
How is maximum speed related to amplitude and angular frequency in SHM?
Jawaban
v_max = ωA. Maximum speed occurs at equilibrium.
Kartu 330
Pertanyaan
For a horizontal ideal spring oscillator, how can kinetic energy at displacement x from equilibrium be found for amplitude A?
Jawaban
K = ½k(A² - x²). Subtract spring potential energy from the constant total.
Kartu 331
Pertanyaan
How far apart in phase are displacement and acceleration in SHM?
Jawaban
Half a cycle, or 180°. When displacement is nonzero, acceleration has the opposite sign; at equilibrium, both are zero.
Kartu 332
Pertanyaan
What is the period of a small-angle simple pendulum of length L when damping is negligible?
Jawaban
T = 2π√(L/g). The simple-pendulum model uses a point-like bob on a light, inextensible string with a fixed support; bob mass doesn't affect the period.
Kartu 333
Pertanyaan
If x(t) is at a positive maximum at t = 0, what qualitative pattern follows over one cycle?
Jawaban
It crosses equilibrium moving negative at T/4, reaches negative maximum at T/2, returns through equilibrium at 3T/4, and reaches maximum positive displacement at T.
Kartu 334
Pertanyaan
At equilibrium, how are a horizontal ideal spring oscillator's energies divided?
Jawaban
Kinetic energy is maximum and spring potential energy is minimum. With x measured from equilibrium, U_s = 0 at x = 0.
Kartu 335
Pertanyaan
An SHM object is at negative displacement and moving toward equilibrium. What signs do velocity and acceleration have if positive is right?
Jawaban
Both are positive. Motion and restoring acceleration point right toward equilibrium.
Kartu 336
Pertanyaan
How does a pendulum's period change if its length becomes nine times as large?
Jawaban
The period triples. T is proportional to √L.
Kartu 337
Pertanyaan
If SHM starts at maximum positive displacement, what equation gives its position?
Jawaban
x(t) = A cos(2πft). A is amplitude, f is frequency, and t is elapsed time.
Kartu 338
Pertanyaan
What feature would rule out ideal SHM in a force-versus-displacement-from-equilibrium graph?
Jawaban
A restoring-force relationship that is not a straight line through the origin over the motion's range. Ideal SHM needs F ∝ -x.
Kartu 339
Pertanyaan
At a horizontal ideal spring oscillator's turning points, how are kinetic and spring potential energy divided?
Jawaban
Kinetic energy is zero and spring potential energy is maximum. The object momentarily stops at |x| = A.
Kartu 340
Pertanyaan
For the same ideal spring with negligible damping and spring mass, which graph can determine k from measured periods and attached masses?
Jawaban
Graph T² versus m. For T = 2π√(m/k), the slope is 4π²/k.
Kartu 341
Pertanyaan
What makes a substance a fluid?
Jawaban
It deforms continuously under a shear force and takes the shape of its container. Liquids and gases are fluids.
Kartu 342
Pertanyaan
What is mass density?
Jawaban
Mass per volume: ρ = m/V. Its SI unit is kg/m³.
Kartu 343
Pertanyaan
For pressure that is uniform over a surface patch, how is it related to normal force and area?
Jawaban
P = F_perpendicular/A. Pressure is a scalar field even though the contact force has direction.
Kartu 344
Pertanyaan
What is volume flow rate?
Jawaban
Volume passing a cross-section per time: Q = ΔV/Δt. Its SI unit is m³/s.
Kartu 345
Pertanyaan
What is the buoyant-force magnitude on an object immersed in a static fluid whose density is uniform over the displaced volume?
Jawaban
The weight of the displaced fluid: F_B = ρ_fluid gV_displaced. Here ρ_fluid is the uniform density over that volume.
Kartu 346
Pertanyaan
What conditions support the basic Bernoulli model used here?
Jawaban
Steady, incompressible, nonviscous flow along the compared flow path, with a completely filled pipe unless stated otherwise. Incompressible means a moving fluid element's density stays effectively constant. Pumps or major dissipative effects require extra terms.
Kartu 347
Pertanyaan
Under the ideal model, how does average density predict whether a free object floats or sinks?
Jawaban
It floats if its average density is less than the fluid's and sinks if it is greater. Equal average density gives neutral buoyancy when fully submerged; assume no support or other external force.
Kartu 348
Pertanyaan
How are volume flow rate, cross-sectional area, and average fluid speed normal to that area related?
Jawaban
Q = Av. This gives the volume crossing a completely filled pipe section per time.
Kartu 349
Pertanyaan
How does a static fluid exert force on a surface?
Jawaban
Many particle–surface interactions produce a net force perpendicular to the surface. A static fluid does not exert a tangential shear force.
Kartu 350
Pertanyaan
How does pressure change with depth in a static uniform fluid?
Jawaban
It increases by ΔP = ρgΔh. Greater depth means more fluid weight above each unit area.
Kartu 351
Pertanyaan
What force balance holds for an object floating at rest when buoyancy and weight are its only vertical forces?
Jawaban
F_B = mg. The object's weight equals the weight of the fluid it displaces.
Kartu 352
Pertanyaan
What is the continuity equation for steady incompressible flow in one filled pipe?
Jawaban
A₁v₁ = A₂v₂. The same volume flow rate passes each cross-section.
Kartu 353
Pertanyaan
Why does a static fluid produce an upward buoyant force?
Jawaban
Pressure is greater on the object's lower surfaces than on its upper surfaces. The vertical pressure forces do not cancel.
Kartu 354
Pertanyaan
What is the absolute pressure at depth h below the open surface of a static, uniform liquid?
Jawaban
P_abs = P_atm + ρgh. ρgh is the gauge pressure from the liquid column.
Kartu 355
Pertanyaan
Immediately after a fully submerged object is released in a static, uniform ideal fluid, which way does it accelerate if its average density exceeds the fluid density and only weight and buoyancy act?
Jawaban
Downward. Weight exceeds buoyant force, so the initial net force and acceleration point downward.
Kartu 356
Pertanyaan
Water's average speed normal to a 0.020 m² pipe cross-section is 3 m/s. What is the volume flow rate?
Jawaban
0.060 m³/s. Q = Av = 0.020×3.
Kartu 357
Pertanyaan
What does the slope of a mass-versus-volume graph represent for one uniform material?
Jawaban
Density. Since m = ρV, the line's slope is ρ.
Kartu 358
Pertanyaan
How do gauge pressure and absolute pressure differ?
Jawaban
Gauge pressure is measured relative to atmospheric pressure; absolute pressure is measured relative to vacuum. P_abs = P_atm + P_gauge.
Kartu 359
Pertanyaan
For a fully submerged rigid object in a static, incompressible, uniform fluid, does buoyant force increase with depth?
Jawaban
No. Displaced volume, fluid density, and g stay constant, so F_B stays constant despite higher absolute pressure.
Kartu 360
Pertanyaan
For steady incompressible flow in a filled pipe, what happens to speed if cross-sectional area halves?
Jawaban
It doubles. Continuity keeps Av constant.
Kartu 361
Pertanyaan
When does a fluid element's velocity change?
Jawaban
Its velocity changes when a nonzero net force acts on it. Pressure forces and gravity can contribute to that net force.
Kartu 362
Pertanyaan
For steady, incompressible, nonviscous flow along the same flow path, what does Bernoulli's equation express?
Jawaban
Conservation of mechanical energy per unit volume. Along that flow path, P + ½ρv² + ρgy stays constant under the stated conditions.
Kartu 363
Pertanyaan
For a uniform object floating at rest in a uniform-density fluid with buoyancy and weight as its only vertical forces, what fraction of its volume is submerged?
Jawaban
V_sub/V_object = ρ_object/ρ_fluid. A less-dense object floats with a smaller fraction submerged.
Kartu 364
Pertanyaan
For steady incompressible flow in a filled pipe, what happens to speed if pipe radius halves?
Jawaban
It becomes four times as large. Area is proportional to radius squared.
Kartu 365
Pertanyaan
What does Pascal's principle say for a confined incompressible fluid at rest?
Jawaban
An applied pressure change is transmitted throughout the fluid. The same pressure change acts at every connected point.
Kartu 366
Pertanyaan
In a uniform static fluid, what does the slope of gauge pressure versus depth represent?
Jawaban
ρg. For known g, the slope can determine fluid density.
Kartu 367
Pertanyaan
Immediately after a fully submerged object is released in a static, uniform ideal fluid, which way does it accelerate if its average density is less than the fluid density and only weight and buoyancy act?
Jawaban
Upward. Buoyant force exceeds weight, so the initial net force and acceleration point upward.
Kartu 368
Pertanyaan
For steady incompressible flow in a filled pipe, area narrows from 0.040 m² to 0.010 m². If initial speed is 2 m/s, what is final speed?
Jawaban
8 m/s. Continuity gives v₂ = A₁v₁/A₂.
Kartu 369
Pertanyaan
What physical quantity does each term in P + ½ρv² + ρgy share?
Jawaban
Energy per unit volume, equivalent to pressure. Every term uses units of pascals.
Kartu 370
Pertanyaan
In one static fluid of uniform density, what experimental graph could test F_B = ρ_fluid gV_displaced?
Jawaban
Graph measured buoyant force versus displaced volume. A line with slope near ρ_fluid g supports the model.
Kartu 371
Pertanyaan
A uniform object of density 750 kg/m³ floats at rest in uniform-density water of density 1000 kg/m³, with buoyancy and weight as its only vertical forces. What fraction is submerged?
Jawaban
0.75, or 75%. Use the density ratio for floating equilibrium.
Kartu 372
Pertanyaan
A main pipe splits into two outlets during steady incompressible flow. What flow-rate relation holds?
Jawaban
Incoming flow rate equals the sum of outgoing flow rates. Q_in = Q_out,1 + Q_out,2.
Kartu 373
Pertanyaan
For steady, incompressible, nonviscous efflux with negligible losses, what is Torricelli's speed for an opening a vertical distance h below a large open surface?
Jawaban
v = √(2gh). Both locations are open to atmospheric pressure, and the large surface makes the upper-fluid speed negligible.
Kartu 374
Pertanyaan
Why does the same force create more pressure on a smaller area?
Jawaban
Pressure is inversely proportional to area for fixed perpendicular force. Concentrating the force raises F/A.
Kartu 375
Pertanyaan
A sample has mass 0.60 kg and volume 2.0×10⁻⁴ m³. What is its density?
Jawaban
3.0×10³ kg/m³. Divide mass by volume.
Kartu 376
Pertanyaan
What conservation law underlies the continuity equation for incompressible flow?
Jawaban
Conservation of mass. Constant density turns equal mass flow into equal volume flow.
Kartu 377
Pertanyaan
An immersed object rests on a scale that exerts an upward support force. If weight, buoyancy, and that support are its only vertical forces, with mg ≥ F_B, how is apparent weight related to buoyant force?
Jawaban
N = mg - F_B. Here N is the upward scale-force magnitude. The fluid supports part of the object's weight, so the scale reading is no greater than its weight under the stated condition.
Kartu 378
Pertanyaan
What is the SI unit of pressure?
Jawaban
The pascal, Pa. One pascal equals 1 N/m².
Kartu 379
Pertanyaan
How do pressures compare at the same horizontal level in one connected static fluid?
Jawaban
They are equal. Container shape does not change pressure at a fixed elevation.
Kartu 380
Pertanyaan
What does specific gravity compare?
Jawaban
A substance's density with water's density. It is a dimensionless ratio, commonly ρ_substance/ρ_water.
Kartu 381
Pertanyaan
How could collecting outflow test a volume flow rate predicted from area and average normal speed?
Jawaban
Measure collected volume over a timed interval and compare ΔV/Δt with Av. Repeat trials and include volume and timing uncertainty.
Kartu 382
Pertanyaan
How does the particle model distinguish a fluid from a rigid solid?
Jawaban
Fluid particles can rearrange and flow past one another. A rigid solid resists sustained shape change.
Kartu 383
Pertanyaan
At equal height along the same flow path in steady, incompressible, nonviscous flow, how are pressure and speed related?
Jawaban
The faster region has lower static pressure. Along that flow path at equal height, P + ½ρv² remains constant.
Kartu 384
Pertanyaan
A fully submerged object displaces 0.020 m³ of static water. Using ρ = 1000 kg/m³ and g = 10 m/s², what is F_B?
Jawaban
200 N. F_B = ρgV = 1000×10×0.020.
Kartu 385
Pertanyaan
Why can a steel ship float even though steel is denser than water?
Jawaban
Its hollow shape makes the ship's overall average density less than water. It displaces enough water for buoyant force to balance weight.
Kartu 386
Pertanyaan
How does an ideal hydraulic lift with a confined incompressible fluid at rest multiply force?
Jawaban
Equal pressure change gives F₁/A₁ = F₂/A₂. The larger-area piston produces the larger force.
Kartu 387
Pertanyaan
For steady, incompressible, nonviscous efflux with negligible losses, what graph can test Torricelli's relation while fluid head h varies?
Jawaban
Graph v² versus h. With both locations open to atmospheric pressure and upper-surface speed negligible, the model predicts slope 2g.
Kartu 388
Pertanyaan
What does incompressible mean in the introductory ideal-fluid model?
Jawaban
A fluid element's density stays effectively constant as it moves. Its volume does not appreciably shrink under pressure changes.
Kartu 389
Pertanyaan
At two points along the same flow path in steady, incompressible, nonviscous flow, how are pressure and height related when speed is equal?
Jawaban
Pressure is lower at the higher point. P + ρgy remains constant.
Kartu 390
Pertanyaan
How can water displacement measure an irregular solid's volume?
Jawaban
Submerge it fully and measure the increase in displaced-water volume. The volume change equals the submerged solid's volume if no water enters it.
Kartu 391
Pertanyaan
Two equal-volume samples have densities ρ and 3ρ. How do their masses compare?
Jawaban
The denser sample has three times the mass. From m = ρV, mass scales with density at fixed volume.
Kartu 392
Pertanyaan
How can scale readings in air and water determine buoyant force?
Jawaban
Subtract the immersed scale reading from the air reading. When the object is at rest and air buoyancy is negligible, the decrease equals the liquid's buoyant force.
Kartu 393
Pertanyaan
Static water has ρ = 1000 kg/m³. Using g = 10 m/s², what gauge pressure is 3 m below its open surface?
Jawaban
30,000 Pa. P_gauge = ρgh = 1000×10×3.
Kartu 394
Pertanyaan
During steady incompressible outflow, why can a large tank's top-surface speed be neglected compared with outlet speed?
Jawaban
The tank's surface area is much larger than the outlet area. Continuity then makes the top-surface speed much smaller.
Kartu 395
Pertanyaan
For a chosen fluid element in a horizontal region, what can a pressure difference do?
Jawaban
It creates a net pressure force from higher pressure toward lower pressure and can accelerate the element by Newton's second law. Other forces must also be included when they matter.
Kartu 396
Pertanyaan
How can buoyancy measurements in a static fluid of known uniform density determine an irregular object's volume?
Jawaban
Measure buoyant force while the object is fully submerged, then use V = F_B/(ρ_fluid g). The fluid density must be uniform over the displaced volume.
Kartu 397
Pertanyaan
A 200 N perpendicular force acts on area 0.040 m². What pressure does it create?
Jawaban
5,000 Pa. P = F/A = 200/0.040.
Kartu 398
Pertanyaan
Why doesn't a hydraulic lift multiply energy?
Jawaban
The large-force piston moves a shorter distance. Ideally, input work equals output work.
Kartu 399
Pertanyaan
A large open tank has steady, incompressible, nonviscous efflux with negligible losses. Using g = 10 m/s², what speed leaves an opening 5 m below the surface when upper-surface speed is negligible?
Jawaban
10 m/s. Both locations are at atmospheric pressure, so v = √(2gh) = √100.
Kartu 400
Pertanyaan
An object floats first in water and then in a denser liquid. How does its submerged fraction change?
Jawaban
It decreases in the denser liquid. Less displaced volume is needed to provide the same buoyant force.

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400 kartu