# How do you calculate the change in momentum of an object?

##### 1 Answer

There are two possible ways depending on the problem.

1) The change in momentum of an object is its mass times the change in its velocity.

Example) A 3kg mass initially moving 4m/s to the right rebounds off of a wall and begins travelling to the left at 2m/s.

Taking "right" to be the positive direction:

2) The change in the momentum of an object can also be found by considering the force acting on it. If a force,

Remember to use the right sign when substituting

Lastly, if your object is moving both horizontally and vertically then