# Linear Momentum

Momentum is a physical quantity which is useful in understanding Newtonâ€™s second law. It is a measure of the inertia of motion. It is also the ability of a body to impart motion to another body or the quantity of motion contained in a body. Momentum depends on two factors, namely- mass of the body and
- velocity of the body.

*The linear momentum of a body is defined as the product of its mass and velocity.*

If

*m*is the mass of the body and

*v*is its velocity, the momentum

*p*of the body is given by

*p*=

*mv*

It is a vector
The SI unit of momentum is kg m s
Newtonâ€™s second law of motion can also be stated as â€˜
Therefore, Newtonâ€™s second law can be written in terms of momentum as follows:

**in the direction of velocity.**^{âˆ’1}.*the rate of change of momentum of a body is proportional to the applied force and takes place in the direction of the forceâ€™.**F*=

*ma*

Thus, the resultant force on a body is equal to change in linear momentum per unit time.