Available practice: 73 of 75 marks. Parts 7(a) await marking support. Scores cover available parts only. Theory Paper 2: Section A is compulsory and Section B offers a choice of two questions. Four published mark-scheme discrepancies across the two variants are held from automatic marking.
(a)A sky-diver jumps from a stationary balloon. His initial downwards acceleration is 10 m / s2. Fig. 1.1 shows the directions of the air resistance and the weight of the sky-diver. The mass of the sky-diver is 60 kg and his weight is 600 N. Explain, using ideas about the forces, why his initial downwards acceleration is 10 m / s2.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[2 marks]
(b)When the sky-diver in Fig. 1.1 opens the parachute, he accelerates upward for a short time. Explain why, comparing the upward air resistance with his 600 N weight.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[1 mark]
(c)(i)After the sky-diver opens the parachute, air resistance varies with speed as in Fig. 1.2. His weight is 600 N. Determine his terminal speed from the graph.
Answer guidance
Determine Work it out from what you are given or from the figure, and show how you got there.
[1 mark]
(c)(ii)After the sky-diver opens the parachute, air resistance varies with speed as in Fig. 1.2. His weight is 600 N. Calculate the resultant force on him at 5.5 m/s.
Answer guidance
Calculate Show your working. The method can earn marks even when the final value is wrong, and a bare answer often cannot.
[1 mark]
5054/21/M/J/16Cambridge O Level Physics 5054 · May/June 2016 · Paper 2 variant 1 · Question 1