Original: Acceleration due to gravity varies over the surface of the Earth , generally increasing from about 9.78 m\/s2 ( 32.1 ft\/s2 ) at the equator to about 9.83 m\/s2 ( 32.3 ft\/s2 ) at the poles .
Simplified: The pound-force is about equal to the gravitational force applied on a mass of one pound on the surface of Earth .