Impulse and force-momentumEdexcel A-Level Physics: Mind map

Exam questions on Impulse and force-momentum

1. A tennis ball of mass 0.058 kg approaches a racket horizontally at 20 m s⁻¹. It is in contact with the strings for 5.0 ms and leaves the racket in the opposite direction at 30 m s⁻¹.
   The ball has the same incoming and outgoing speeds, but a different racket keeps the ball in contact for longer. Explain the effect on the average force on the ball.2 marks
2. A driver of mass 70 kg, wearing a seat belt, is travelling at 15 m s⁻¹ when the car hits a wall. The seat belt and an airbag bring the driver to rest in 0.12 s.
   Calculate the average force on the driver while being stopped.2 marks
3. A student investigates the relationship between force and change of momentum. A trolley of mass 0.800 kg moves towards a force sensor at 0.80 m s⁻¹, measured by a light gate, and rebounds at 0.55 m s⁻¹. The data logger connected to the sensor shows that the collision lasts 0.045 s and gives the impulse, found from the area under the recorded force against time, as 1.05 N s.
   Calculate the change in momentum of the trolley. Compare it with the impulse given by the data logger and state whether the results support the relationship FΔt = Δp.3 marks