Acceleration of Gravity

The acceleration of a freely falling body caused by the pull of gravity. Acceleration caused by gravity is expressed as the rate of increase of velocity over a given unit of time. This rate, in a vacuum, near sea level at a location of 40° north latitude is 32.2 feet per Square second, or 9.8 meters  per Square second. This acceleration decreases with an increase in altitude until it becomes zero outside of the earth's gravitational field