Momentum & collisions worksheet with answers

A 6 kg rifle, free to move, fires a 12 g bullet at 350 m/s. Both start at rest. Find the recoil speed V of the rifle.

An 800 kg car moving at 9 m/s runs into a stationary 1600 kg car. The cars lock together. Find their common velocity v′ just after the collision (positive in the first car’s direction).

A 1 kg glider moving at 9 m/s makes a perfectly elastic head-on collision with a 1.5 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 16 kg projectile moving horizontally at 11 m/s explodes into two fragments that move along the same line. The 13 kg fragment continues forwards at 35 m/s. Find the velocity v′₂ of the 3 kg fragment (positive in the original direction).

An 8 g bullet is fired horizontally into a 4.5 kg block hanging from light strings 1.1 m long, and stays in it. The strings swing out to a largest angle of 30° from the vertical. Use g = 9.81 m/s². Find the speed v of the bullet before impact.

A 0.3 kg ball hits a wall at 17 m/s and bounces straight back at 8 m/s. The contact lasts 20 ms. Find the magnitude of the impulse J the wall gives the ball.