# Definition:Gravity

## Definition

Gravity is the tendency of bodies with mass to attract each other.

### Force of Gravity on Earth

When used in an unqualified sense, it is usual for the term force of gravity to mean the downward force on a body at the surface of Earth.

From Gravity at Earth's Surface, this is approximately $9.8 \ \mathrm N \ \mathrm{kg}^{-1}$

The force of gravity varies across the Earth's surface, and therefore it makes little sense to use it as a standard.

However, the CGPM adopted a standard value of Acceleration Due to Gravity at Earth's Surface of $9.806 \, 65 \ \mathrm N \ \mathrm{kg}^{-1}$ in $1901$.

### Gravitational Force

The gravitational force on a body $B$ is the force which is exerted on $B$ as a result of the gravitational field whose influence it is under.

## Also known as

Gravity is also known as gravitation.

In common usage it is often referred to as the force of gravity, in particular at the surface of Earth.

## Also see

• Results about gravity can be found here.

## Linguistic Note

The word gravity derives from a Latin word meaning weighty.