You may use a calculator. You should show all your working and use appropriate units. Take the weight of 1.0 kg to be 9.8 N (acceleration of free fall = 9.8 m/s²).
(a)(i)
Fig. 1.1 is the speed-time graph for a stone as it falls to the ground.
On Fig. 1.1, mark:
• a letter X to indicate a point where the rock is moving with a constant speed
• a letter Y to indicate a point where the rock is decelerating.
[2 marks]
(a)(ii)
At time t = 0, the acceleration of the stone is equal to the acceleration of free fall.
Give the name of the force accelerating the stone at time t = 0.
Answer guidance
State A short answer. No explanation is needed, and adding one cannot earn extra marks.
[1 mark]
(b)(i)
The weight of the stone is 4.0 N.
As the stone falls, the force F of air resistance acting on the rock changes.
State the value of F at time t = 0.
F = ...................................... N
Answer guidance
State A short answer. No explanation is needed, and adding one cannot earn extra marks.
[1 mark]
(b)(ii)
State the value of F at time t = 10.0 s.
F = ...................................... N
Answer guidance
State A short answer. No explanation is needed, and adding one cannot earn extra marks.
[1 mark]
(b)(iii)
Suggest why F changes between t = 0 s and t = 10.0 s
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[1 mark]
(c)(i)
Using Fig. 1.1, determine the acceleration of the rock at time t = 4.0 s. State the unit of your answer.
You will need to draw a tangent to the graph in Fig. 1.1 and show your working.
acceleration = ...................................... unit = ..........
Answer guidance
Draw Accuracy is being marked. Use the figure and be precise about position and labels.
[3 marks]
(c)(ii)
The mass of the stone is 408 g.
Determine the force F of air resistance acting on the rock at time t = 4.0 s.
Show your working.
F = ...................................... N
Answer guidance
Show The result is given, so every step of the reasoning is what earns the marks.
[2 marks]
5054/02/SP/23Cambridge O Level Physics 5054 · Specimen 2023 · Paper 2 · Question 1