Practice Conservation of Momentum in Physics

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

In a closed system with no external forces, total momentum before = total momentum after.

Momentum can move between objects but can't be created or destroyed.

Example 1

medium
A 5 \text{ kg} cart moving at 4 \text{ m/s} collides with a stationary 3 \text{ kg} cart. They stick together. What is their final velocity?

Example 2

hard
A 2 \text{ kg} ball moving at 6 \text{ m/s} right collides elastically with a 2 \text{ kg} ball at rest. What are the final velocities?

Example 3

medium
A 60 \text{ kg} astronaut floating in space throws a 5 \text{ kg} tool at 8 \text{ m/s}. What is the astronaut's recoil velocity?

Example 4

medium
A 4 \text{ kg} firework initially at rest explodes into a 1 \text{ kg} piece moving east at 12 \text{ m/s} and a 3 \text{ kg} piece moving west. What is the speed of the 3 \text{ kg} piece?
← Back to Conservation of Momentum Worked Examples