Momentum is the tendency for an object to keep moving with the same speed and direction.
How can we change momentum?
It takes unbalanced Forces to change the momentum of an object.
Why do we need unbalanced forces?
Unbalanced Forces being needed to cause objects to:
- stop or start moving,
- change their speed,
- direction of motion
These are all forms of acceleration (qualitative only).
What is acceleration dependent on?
The acceleration is in the direction of resultant Force and the speed of the change is dependent on the size of the Force.