Momentum & collisions worksheet with answers

A 0.45 kg ball at rest is kicked. The foot pushes it with an average force of 750 N for 5 ms. Find the speed v of the ball just after the kick.

A 1800 kg car moving at 20 m/s collides head-on with a 600 kg car moving at 11 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 8 m/s explodes into two fragments that move along the same line. The 1 kg fragment continues forwards at 48 m/s. Find the velocity v′₂ of the 6 kg fragment (positive in the original direction).

A 20 g bullet is fired horizontally into a 3 kg wooden block hanging on light strings, and stays inside it. The block swings up until it is 20 cm higher than at the start. Use g = 9.81 m/s². Find the speed v of the bullet before impact.

A 0.1 kg ball hits a wall at 12 m/s and bounces straight back at 12 m/s. The contact lasts 10 ms. Find the average force F_avg of the wall on the ball.

A 15 g bullet is fired horizontally into a 2.5 kg block hanging from light strings 2 m long, and stays in it. The strings swing out to a largest angle of 25° from the vertical. Use g = 9.81 m/s². Find the speed v of the bullet before impact.