# Gravity

The center of gravity of a body is the point at which we can consider its whole weight to be concentrated.

In our formulas we use the "acceleration of gravity" number. This value is about 980 centimeters per second per second or 32.2 feet per second per second.

These numbers vary little on the earth surface

- At the equator gravity is about 978 centimeters-per-second per second.
- At the poles gravity is 983 centimeters-per-second per second