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An aeroplane is 4000 m above the Earth's surface - AQA - GCSE Physics - Question 8 - 2019 - Paper 1
Question 8
An aeroplane is 4000 m above the Earth's surface. A skydiver jumps from the aeroplane and falls vertically. Figure 15 shows the distance the skydiver falls during ... show full transcript
Worked Solution & Example Answer:An aeroplane is 4000 m above the Earth's surface - AQA - GCSE Physics - Question 8 - 2019 - Paper 1
Step 1
Step 2
Explain the changing motion of the skydiver in terms of the forces acting on the skydiver.
Answer
Initially, the skydiver accelerates downwards due to the force of gravity being greater than air resistance. As the skydiver gains speed, air resistance increases and begins to counteract the gravitational force. Eventually, the resultant force becomes zero, and the skydiver reaches terminal velocity, where they fall at a constant speed.
Step 3
Use Figure 15 to determine the speed of the skydiver between 7 seconds and 12 seconds.
Answer
At 7 seconds, the distance fallen is 200 m, and at 12 seconds, the distance is 450 m. The distance fallen between these two times is:
450 m - 200 m = 250 m.
The time taken for this distance is: 12 s - 7 s = 5 s.
Thus, the speed is calculated as:
Step 4
Explain why the skydiver from 39,000 metres reached a higher speed than from 4000 metres.
Answer
The higher the altitude, the less dense the air is. Therefore, as the skydiver falls from 39,000 m, the air resistance acts less on them compared to a skydiver falling from 4000 m. This reduced air resistance allows the skydiver to accelerate for a longer period before reaching a higher terminal velocity.