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2.3 – Work, energy, and power - IB Questionbank | RevisionDojo

Practice 2.3 – Work, energy, and power with authentic IB Physics exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like mechanics, thermodynamics, and waves. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.

Paper

Level

Question 1

SLPaper 2

This question is about the motion of a bicycle. A cyclist is moving up a slope that is at an angle of 19° to the horizontal. The mass of the cyclist and the bicycle is 85 kg.

Calculate the component of the weight of the cyclist and bicycle parallel to the slope.

[2]

Calculate the normal reaction force on the bicycle from the slope.

[1]

At the bottom of the slope the cyclist has a speed of 5.5 m s⁻¹. The cyclist stops pedalling and applies the brakes which provide an additional decelerating force of 250 N. Determine the distance taken for the cyclist to stop. Assume air resistance is negligible and that there are no other frictional forces.

[4]

Question 2

HLPaper 1A

A projectile is fired from level ground with speed $v$ at an angle $heta$ to the ground. Ignoring air resistance, which of the following is a correct expression for the maximum height reached by the projectile?

Question 3

SLPaper 1A

A stone is falling at a constant velocity vertically down a tube filled with oil. Which of the following statements about the energy changes of the stone during its motion are correct?

I. The gain in kinetic energy is less than the loss in gravitational potential energy.

II. The sum of kinetic and gravitational potential energy of the stone is constant.

III. The work done by the force of gravity has the same magnitude as the work done by friction.

Question 4

HLPaper 1A

The graph shows the variation with time of the velocity of a truck of fixed mass.

What can be deduced from the graph?

Question 5

HLPaper 1A

A body starting from rest moves along a straight-line under the action of a constant force. After travelling a distance $d$ the speed of the body is $v$ .

The speed of the body when it has travelled a distance $\frac{d}{2}$ from its initial position is

Question 6

HLPaper 1A

A vehicle is driven up a hill at constant speed. Which of the following best describes the energy changes involved?

Question 7

SLPaper 1A

An object of mass $2m$ moving at velocity $3v$ collides with a stationary object of mass $4m$ . The objects stick together after the collision. What is the final speed and the change in total kinetic energy immediately after the collision?

	Final speed	Change in total kinetic energy
A.	$v$	$3mv^2$
B.	$v$	$6mv^2$
C.	$2v$	$3mv^2$
D.	$2v$	$6mv^2$

Question 8

HLPaper 2

This question is about finding the force that acts upon a car when it is in a head on collision. In order to measure collision forces a car is crashed head-on into a flat, rigid barrier and the resulting crush distance d is measured. The crush distance is the amount that the car collapses in coming to rest. In the above diagram the crush distance $d=L_1-L_2$ .

Show that the average crush force exerted on a car of mass m with impact speed v is equal to $\frac{mv^2}{2d}$ .

[2]

The table below gives values of the crush distance, d, for different impact speeds v, of cars of the same make. (Uncertainties in measurement are not given.)

$v / ms^{-1}$	$d / m$	$\frac{v^2}{d} / ms^{-2}$
0	0	0
3.0	0.08	..........
10.0	0.35	..........
15.0	0.65	..........
20.0	1.02	..........

Complete the last column of the table.

[1]

Plot a graph of $\frac{v^2}{d}$ against v.

[4]

Consider the situation in which a car of mass 1200 kg has an impact speed of 12 $m \, s^{-1}$ . Use information from the graph you have drawn to find the average force exerted on the car during the collision as it is brought to rest.

[2]

Calculate the time it takes this car to come to rest from the moment of impact.

[2]

Question 9

HLPaper 1A

A girl is standing on a moving skateboard. She pushes backwards on the ground at intervals as shown on the graph.

How much kinetic energy is gained by the girl during the period represented on the graph? Frictional forces are negligible.

Question 10

SLPaper 1A

The tension in a horizontal spring is directly proportional to the extension of the spring. The energy stored in the spring at extension $x$ is $E$ . What is the work done by the spring when its extension changes from $x$ to $\frac{x}{4}$ ?

2.3 – Work, energy, and power Questionbank