1.Easy
A 3 kg rifle, free to move, fires a 15 g bullet at 800 m/s. Both start at rest. Find the recoil speed V of the rifle.
M = 3 kgm = 15 gv = 800 m/s
V = m/s
Momentum & collisions worksheet with answers
2.Easy
A 700 kg car moving at 11 m/s runs into a stationary 500 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 700 kgv1 = 11 m/sm2 = 500 kgv2 = 0 m/s
v′ = m/s
3.Medium
A 5 kg glider moving at 3 m/s makes a perfectly elastic head-on collision with a 4 kg glider at rest on a frictionless track. Find the velocity v′1 of the first glider after the collision (positive in its original direction).
m1 = 5 kgm2 = 4 kgv1 = 3 m/sv2 = 0
v′1 = m/s
4.Medium
A 600 kg car moving at 25 m/s runs into a stationary 1700 kg car and the two lock together. How much kinetic energy ΔK is lost in the collision?
m1 = 600 kgv1 = 25 m/sm2 = 1700 kgv2 = 0
ΔK = J
5.Hard
A 0.6 kg ball hits a wall at 19 m/s and bounces straight back at 9 m/s. The contact lasts 40 ms. Find the magnitude of the impulse J the wall gives the ball.
m = 0.6 kgvin = 19 m/svout = 9 m/sΔt = 40 ms
J = N·s
6.Hard
A 1100 kg car runs into a parked 1900 kg car. The wrecks lock together and skid 13 m before stopping. The coefficient of kinetic friction between tyres and road is 0.6. Use g = 9.81 m/s². Find the speed v1 of the first car just before the collision.
m1 = 1100 kgm2 = 1900 kgd = 13 mμ = 0.6g = 9.81 m/s²
v1 = m/s
Answer key
- 1. V = 4 m/s
- 2. v′ = 6.417 m/s
- 3. v′1 = 0.3333 m/s
- 4. ΔK = 138587 J
- 5. J = 16.8 N·s
- 6. v1 = 33.74 m/s
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