1.Easy
A 1100 kg car moving at 17 m/s runs into a stationary 1100 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 1100 kgv1 = 17 m/sm2 = 1100 kgv2 = 0 m/s
v′ = m/s
Momentum & collisions worksheet with answers
2.Easy
A 1900 kg car moving at 10 m/s collides head-on with a 1500 kg car moving at 3 m/s in the opposite direction. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).
m1 = 1900 kgv1 = 10 m/sm2 = 1500 kgv2 = −3 m/s
v′ = m/s
3.Medium
A 0.5 kg glider moving at 12 m/s makes a perfectly elastic head-on collision with a 1 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 = 0.5 kgm2 = 1 kgv1 = 12 m/sv2 = 0
v′1 = m/s
4.Medium
A 700 kg car moving at 5 m/s runs into a stationary 1800 kg car and the two lock together. What percentage ΔK/K of the original kinetic energy is lost?
m1 = 700 kgv1 = 5 m/sm2 = 1800 kgv2 = 0
ΔK/K = %
5.Hard
A 0.4 kg ball hits a wall at 26 m/s and bounces straight back at 11 m/s. The contact lasts 20 ms. Find the average force Favg of the wall on the ball.
m = 0.4 kgvin = 26 m/svout = 11 m/sΔt = 20 ms
Favg = N
6.Hard
At a crossing a 1800 kg car travelling east at 18 m/s collides with a 1500 kg car travelling north at 25 m/s. The cars lock together. Find the speed v′ of the wreck just after the collision.
m1 = 1800 kgv1 = 18 m/s (E)m2 = 1500 kgv2 = 25 m/s (N)
v′ = m/s
Answer key
- 1. v′ = 8.5 m/s
- 2. v′ = 4.265 m/s
- 3. v′1 = −4 m/s
- 4. ΔK/K = 72 %
- 5. Favg = 740 N
- 6. v′ = 15.02 m/s
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