Pupil sheet · Momentum and collisions
Momentum and collisions — final check
Name ______________________ Date ____________
Work alone, with the lesson closed. Answer every question; there are no hints.
1. define / calculate / state
A 0.40 kg trolley moves to the right at 3.0 m/s. (a) Define momentum. (b) Calculate the momentum of the trolley. (c) It hits a 0.20 kg trolley at rest and they stick together. Calculate their velocity. (d) In another collision, the 0.40 kg trolley at 3.0 m/s hits a 0.80 kg trolley at rest and bounces back to the left at 0.20 m/s. Calculate the velocity of the 0.80 kg trolley. (e) State the principle you used in (c) and (d).
(a) Definition
(b) Momentum
(c) Velocity after sticking
(d) Velocity of the 0.80 kg trolley
(e) Principle
2. define / calculate / explain
In a crash test, a 1400 kg car hits a barrier at 15 m/s and stops. (a) Define impulse. (b) Calculate the change in momentum of the car. (c) The car’s crumple zone makes it stop in 0.14 s. Calculate the average force on the car. (d) A car without a crumple zone stops in 0.050 s. Calculate the average force on it. (e) Define resultant force in terms of momentum, and use it to explain why the crumple zone makes the crash safer.
(a) Definition of impulse
(b) Change in momentum
(c) Force with crumple zone
(d) Force without
(e) Definition and explanation