CourseCourseConceptConceptDocumentDocument

CAIE A-Level Physics AS 5.2 Gravitational Potential Energy and Kinetic Energy Questions

Practise deriving and applying gravitational and kinetic-energy relations, then combining them in conservation, braking and acceleration problems.

Syllabus
2028–2030
Course
Physics 9702
Level
AS

Exam points

  • derive and use gravitational potential energy changes ΔEP = mgΔh in a uniform field
  • derive and use kinetic energy EK = 1/2 mv² and connect it to changes in motion
  • combine gravitational and kinetic energy in conservation-of-energy, braking and acceleration problems

Covered syllabus points

5.2.1—W = Fs, the formula ∆EP = mg∆h for gravitational potential energy changes in5.2.2—The formula ∆EP = mg∆h for gravitational potential energy changes in a5.2.3—The equations of motion, the formula for kinetic energy EK = 1/2 mv25.2.4—EK = 1/2 mv2

Question 1

[Maximum number: 1]

The change in gravitational potential energy ΔE\Delta E of an object of mass m when moving through height Δh\Delta h near the surface of the Earth is given by the equation shown.

ΔE=mgΔh\Delta E=m g \Delta h

Which equation is needed as part of the derivation of this expression?

A

kinetic energy =12×=\frac{1}{2} \times mass ×( speed )2\times(\text { speed })^{2}

B

moment = force × distance

C

weight = mass × acceleration of free fall

D

work done = power × time

Question 2

[Maximum number: 1]

An object is in a uniform gravitational field. The graph shows how the change in gravitational

potential energy ΔEP\Delta E_{\mathrm{P}} of the object varies with the vertical distance x moved by the object from a

fixed point.

Figure for Question 2 — CAIE A-Level Physics AS

Which graph shows how the gravitational force F acting on the object varies with distance x ?

A

A

B

B

Figure for Question 2 — CAIE A-Level Physics AS
D

D

A
Option A shown in diagram

Option A shown in diagram

B
Option B shown in diagram

Option B shown in diagram

C
Option C shown in diagram

Option C shown in diagram

D
Option D shown in diagram

Option D shown in diagram

Question 3

[Maximum number: 1]

A student attempts to derive the formula for kinetic energy EKE_{\mathrm{K}}. She begins by considering an object of mass m which is initially at rest. A constant force F applied to the object causes it to accelerate to final velocity v in displacement s. The kinetic energy gained by the object is equal to the work done on the object by the force F.

Which equation would the student not need in order to derive the formula for EKE_{\mathrm{K}} ?

A

F=m a

B

W=F s

C

E=12FsE=\frac{1}{2} F s

D

v2=u2+2asv^{2}=u^{2}+2 a s

All question bank results loaded