free fall, in physics, the state of a body moving solely under the influence of gravitational forces (see gravitation). A body falling freely toward the surface of the earth undergoes an acceleration due to gravity of 32 ft/sec² (9.8 m/sec²), which is symbolized by g.

In mechanics, the state of a body that moves freely in any manner in the presence of gravity. The planets are in free fall in the gravitational field of the Sun. A body in free fall follows an orbit such that the sum of gravitational and inertial forces equals zero. Seealso gravitation; Newton's laws of motion.

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