Science
What is Momentum?
Momentum is a measure of how much motion an object has — it depends on both its mass and its velocity. A heavy, fast object has lots of momentum and is hard to stop. In a closed system, total momentum is always conserved.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains momentum.
Key things to understand
- 1Momentum = mass × velocity.
- 2More mass or speed means more momentum.
- 3It measures how hard something is to stop.
- 4Total momentum is conserved in collisions.
Frequently asked questions
- What is momentum?
- A measure of an object's motion, equal to its mass times its velocity.
- What is conservation of momentum?
- In a closed system with no outside forces, the total momentum stays the same before and after a collision.
- Why is a truck harder to stop than a bike?
- It has far more mass, so at the same speed it carries much more momentum.