Here's why:

* Mass (m): A measure of the amount of matter in an object.

* Velocity (v): A measure of an object's speed and direction.

Momentum (p): A measure of an object's motion, taking into account both its mass and velocity.

Formula: p = m * v

Key points about momentum:

* Direction: Momentum is a vector quantity, meaning it has both magnitude (amount) and direction.

* Conservation: In a closed system, the total momentum remains constant. This means that momentum can be transferred between objects, but it cannot be created or destroyed.

Example:

A bowling ball (high mass) moving slowly (low velocity) has the same momentum as a baseball (low mass) moving very fast (high velocity).