past paper questions that frequently come up

Question 1

forces

Use the ideas of momentum to explain how the layer of foam reduces the risk
of serious injury to a motorbike rider sliding at high speed into the support
post. [ 3 marks]

this is an example but the mark scheme is that same for each question

Answer 1

increases the time taken to stop
decreases rate of change in momentum
reduces the force (on the rider)

Question 2

forces momentum

The skateboard moves backwards as the skateboarder jumps forwards.
Explain, using the idea of momentum, why the skateboard moves backwards. [ 3 marks]

Answer 2

• 1mark = momentum before jumping = momentum after jumping
• 2nd mark before jumping momentum of skateboard was 0
• 3rd mark after jumping skateboard has momentum forwards so must have equal momentum backwards