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