Momentum is the inertia of a body. Conservation of interacting bodies total momentum remains constant given no external forces.

**Collisions**
1. Inelastic : Particles adhere or bounce off in-elastically momentum conserved in collision but energy is not.

2. Elastic : Momentum + Energy conserved so solve using quadratic equations.

Impulse =

Impulse is a force acting over a certain period of time = change of momentum.

## Momentum + Change

Momentum = mv = ft **(Impulse)**

Change of momentum = mu-mv / t = ma

## Newtons laws of Motion

1. A body continues in a state of rest or in uniform motion in a straight line unless acted upon by a force.

2. The state of change of momentum is directly proportional to the resultant applied force taking place in the direction of the resultant force.

3. For every action, there is an equal and opposite reaction.