Free Fall

In Newtonian physics, free fall is any motion of a body where its weight is the only force acting upon it. In the context of General Relativity where gravitation is reduced to a space-time curvature, a body in free fall has no force acting on it and it moves along a geodesic. The present article concerns itself with free fall in the Newtonian domain.

An object in in the technical sense of free fall may not necessarily be falling down in the usual sense of the term. An object moving upwards would not normally be considered to be falling but if it is subject to the force of gravity only, it is said to be in free fall. The moon thus is in free fall.

In a uniform gravitational field, in the absence of any other forces, gravitation acts on each part of the body equally and this is akin to weightlessness, a condition which also obtains when the gravitational field is zero such as when far away from any gravitating body. A body in free fall experiences "0-g".

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.

Read more about Free Fall:  Examples, Free Fall in General Relativity, Record Free Fall Parachute Jumps, Surviving Falls

Other articles related to "free fall, fall, falls, free":

Clinostat - Types and Application
... to the clinostat for simulating microgravity is the free fall machine (FFM) ... samples (such as cell suspensions) are allowed to free fall under gravity for about a metre, with the period of free fall lasting just under a second. 20 g for 20 ms - the "bounce"), and allowed to fall again, and so on ...
Marine Corps Test Unit - Subordinate Training - Reconnaissance Platoon - Parachutist and Jumpmaster Training
... Zweiner led a grueling course, instructing the Marines in Parachute Landing Falls (PLFs), body positioning and positive exits from aircraft ... however, the only Marine in MCTU #1 with free-fall experience ... majority of Marines in the recon platoon to become also free-fall qualified ...
Free Fall - Surviving Falls
... The severity of injury increases with the height of a free fall, but also depends on body and surface features and the manner of body impacts on to the surface ... the height at which 50% of children die from a fall is between four and five storey heights above the ground ... JAT stewardess Vesna Vulović survived a fall of 33,000 feet (10,000 m) on January 26, 1972 when she was aboard JAT Flight 367 ...
Specific Force
... but rather a proper acceleration, which is the acceleration relative to free-fall ... For free bodies, the specific force is the cause of, and a measure of, the body's proper acceleration ... The acceleration of an object free falling towards the earth depends on the reference frame (it disappears in the free-fall frame, also called the inertial frame), but any g-force "acceleration" will be ...
Standard Gravity
... Standard gravity, or standard acceleration due to free fall, usually denoted by g0 or gn, is the nominal gravitational acceleration of an object in a vacuum near the surface of the Earth ... is a nominal midrange value on Earth, originally based on the acceleration of a body in free fall at sea level at a geodetic latitude of 45° ... Although the actual acceleration of free fall on Earth varies according to location, the above standard figure is always used for metrological purposes ...

Famous quotes containing the words fall and/or free:

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