Here's why:
* Momentum (p) is calculated as: p = mv, where:
* m is the mass of the object
* v is the velocity of the object
* If mass (m) stays constant, the only way for momentum (p) to change is if the velocity (v) changes.
Examples of this:
* A car accelerating: Its momentum increases because its velocity increases.
* A ball bouncing off a wall: Its momentum changes direction (and possibly magnitude) due to a change in its velocity.
* A rocket launching: Its momentum increases as its velocity increases.
In essence, a change in momentum directly translates to a change in velocity when mass is constant.
