# A-level Mathematics/Advanced/Basic Mechanics/Momentum and Impulse

## Momentum[edit]

Momentum is a construct of physics defined as the product of mass and velocity. Although it is just a construct, it is very useful as it has some very interesting properties, like being conserved in most interactions. In 4 dimension spacetime employed by relativity, it is also shown to belong with energy and other basic constructs that are conserved in interactions. Mathematically, it is represented by p.

## Impulse[edit]

Impulse is simply the change in momentum, and is represented by I when used in mathematics. It is hardly ever used, and mostly only to demonstrate the concept. We will deal with it with forces in the next page.