Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Forces and Motion
367 practice questions
Topics covered
Practice questions
281–290 of 367
Question 281
5 marks · Hard
Answer and see the solution →A student drops two objects of equal mass but different shapes (a smooth metal ball and a large feather) at the same time from the same height in a classroom. Assume air resistance is significant for the feather.
(a)[2 marks]State which object will reach the floor first and explain your answer.
(b)[3 marks]Describe, in terms of forces, what happens to the feather as it falls until it reaches its terminal velocity.
Question 282
4 marks · Hard
Answer and see the solution →A helicopter drops a small probe of mass 0.60 kg from a height above the ground. The gravitational field strength is 9.8 N/kg. The probe quickly reaches terminal velocity as it falls through the air.
(a)[1 mark]Calculate the weight of the probe.
(b)[3 marks]At terminal velocity, what is the size of the air resistance force acting on the probe? Explain your answer.
Question 283
5 marks · Hard
Answer and see the solution →The diagram below shows the forces acting on a raindrop falling through air. The downward force is the weight of the raindrop and the upward force is air resistance.
Forces on a falling raindrop at three different moments. (a)[4 marks]Describe how the relative sizes of weight and air resistance change as the raindrop falls, and what effect this has on the motion of the raindrop. Refer to what happens at the start, as it speeds up, and at terminal velocity.
(b)[1 mark]Explain why the raindrop does not accelerate at terminal velocity.
Question 284
1 mark · Easy
Answer and see the solution →A tennis ball has a mass of 0.06 kg. It is moving with a velocity of 10 m/s. Calculate the momentum of the tennis ball.
Question 285
1 mark · Easy
Answer and check →Which quantity must be changed if you want to increase the momentum of an object without changing its velocity?
- A.Its mass
- B.Its shape
- C.Its speed
- D.Its position
Question 286
1 mark · Easy
Answer and see the solution →State the law of conservation of momentum.
Question 287
2 marks · Easy
Answer and see the solution →Explain why a rocket moves forward when burning fuel, even in the vacuum of space.
Question 288
2 marks · Easy
Answer and see the solution →A sprinter of mass 70 kg is running at a velocity of 8 m/s. She slows down to a stop in 4 seconds. Calculate her change in momentum and the average force needed to stop her.
Question 289
2 marks · Easy
Answer and see the solution →(a)[1 mark]State the equation linking force, change in momentum, and time.
(b)[1 mark]Give the SI unit of momentum.
Question 290
2 marks · Easy
Answer and see the solution →(a)[1 mark]A small skateboard of mass 2 kg is at rest. A person jumps onto it, giving the skateboard a velocity of 3 m/s. Calculate the momentum of the skateboard after the jump.
(b)[1 mark]If the person and skateboard have a combined mass of 40 kg and move off together at 2 m/s after the jump, what is their total momentum?