# Definition:Force

## Definition

A force is an influence which causes a body to undergo a change in velocity.

Force is a vector quantity.

### Dimension

The dimension of measurement of force is $\mathsf {M L T}^{-2}$.

This arises from Newton's Second Law of Motion and its definition as a mass (of dimension $\mathsf M$) multiplied by an acceleration (of dimension $\mathsf {L T}^{-2}$).

### Units

The units of measurement of force are as follows:

### Newton

The newton is the SI unit of force.

It is defined as being:

The amount of force required to accelerate a mass of one kilogram at a rate of one metre per second squared.

### Dyne

The dyne is the CGS unit of force:

$1 \ \mathrm {dyn} = 1 \ \mathrm g \ \mathrm{cm} \ \mathrm s^{-2}$

Thus we see:

$1 \ \mathrm N = 10^5 \ \mathrm {dyn}$

## Also known as

Some writers and thinkers subdivide the idea of a force into a push or a pull, but such a dichotomy can serve to confuse the fact that they are in fact both forces.

## Linguistic Note

The word force is derived from the Latin word fors meaning strength.