A 1200 kg car moving at 22 m/s collides head-on with a 1500 kg car moving at 13 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).
Momentum & collisions worksheet with answers
A 1300 kg car moving at 20 m/s collides head-on with a 700 kg car moving at 4 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).
A 7 kg projectile moving horizontally at 23 m/s explodes into two fragments that move along the same line. The 6 kg fragment continues forwards at 39 m/s. Find the velocity v′2 of the 1 kg fragment (positive in the original direction).
A 4.5 kg glider moving at 5 m/s makes a perfectly elastic head-on collision with a 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).
A 5 g bullet is fired horizontally into a 2.5 kg block hanging from light strings 1.6 m long, and stays in it. The strings swing out to a largest angle of 40° from the vertical. Use g = 9.81 m/s². Find the speed v of the bullet before impact.
A 0.15 kg ball hits a wall at 15 m/s and bounces straight back at 16 m/s. The contact lasts 40 ms. Find the magnitude of the impulse J the wall gives the ball.
Answer key
- 1. v′ = 2.556 m/s
- 2. v′ = 11.6 m/s
- 3. v′2 = −73 m/s
- 4. v′1 = −0.2632 m/s
- 5. v = 1358 m/s
- 6. J = 4.65 N·s
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