1.Easy
A 900 kg car moving at 9 m/s runs into a stationary 2000 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 900 kgv1 = 9 m/sm2 = 2000 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 3 kg rifle, free to move, fires a 15 g bullet at 550 m/s. Both start at rest. Find the recoil speed V of the rifle.
M = 3 kgm = 15 gv = 550 m/s
V = m/s
3.Medium
A 2 kg glider moving at 2 m/s makes a perfectly elastic head-on collision with a 5 kg glider at rest on a frictionless track. Find the velocity v′2 of the second glider after the collision.
m1 = 2 kgm2 = 5 kgv1 = 2 m/sv2 = 0
v′2 = m/s
4.Medium
A 5 kg glider moving at 6 m/s makes a perfectly elastic head-on collision with a 3.5 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 = 3.5 kgv1 = 6 m/sv2 = 0
v′1 = m/s
5.Hard
A 0.15 kg ball hits a wall at 22 m/s and bounces straight back at 14 m/s. The contact lasts 5 ms. Find the average force Favg of the wall on the ball.
m = 0.15 kgvin = 22 m/svout = 14 m/sΔt = 5 ms
Favg = N
6.Hard
At a crossing a 1900 kg car travelling east at 18 m/s collides with a 1000 kg car travelling north at 16 m/s. The cars lock together. Find the direction θ of the wreck just after the collision, measured north of east.
m1 = 1900 kgv1 = 18 m/s (E)m2 = 1000 kgv2 = 16 m/s (N)
θ = °
Answer key
- 1. v′ = 2.793 m/s
- 2. V = 2.75 m/s
- 3. v′2 = 1.143 m/s
- 4. v′1 = 1.059 m/s
- 5. Favg = 1080 N
- 6. θ = 25.07 °
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