<P> In a uniform gravitational field, in the absence of any other forces, gravitation acts on each part of the body equally and this is weightlessness, a condition that also occurs when the gravitational field is zero (such as when far away from any gravitating body). </P> <P> The term "free fall" is often used more loosely than in the strict sense defined above . Thus, falling through an atmosphere without a deployed parachute, or lifting device, is also often referred to as free fall . The aerodynamic drag forces in such situations prevent them from producing full weightlessness, and thus a skydiver's "free fall" after reaching terminal velocity produces the sensation of the body's weight being supported on a cushion of air . </P> <P> In the Western world prior to the 16th century, it was generally assumed that the speed of a falling body would be proportional to its weight--that is, a 10 kg object was expected to fall ten times faster than an otherwise identical 1 kg object through the same medium . The ancient Greek philosopher Aristotle (384--322 BC) discussed falling objects in Physics (Book VII) which was perhaps the first book on mechanics (see Aristotelian physics). </P> <P> The Italian scientist Galileo Galilei (1564--1642) subjected the Aristotelian theories to experimentation and careful observation . He then combined the results of these experiments with mathematical analysis in an unprecedented way . </P>

What is the weight of freely falling body