Question

What is free fall?

Answer 1

Hint:Let us get some idea about free fall. Free fall is defined in Newtonian physics as the motion of a body in which gravity is the sole force acting on it. A body in free fall has no force acting on it in general relativity, where gravity is reduced to a space-time curvature.

Complete step-by-step solution:
In the technical definition of the term "free fall," an item may or may not be falling down in the common meaning. Although an object going upwards is not typically thought to be falling, it is said to be in free fall if it is merely subjected to the force of gravity. The Moon is thus in free fall around the Earth, despite the fact that its orbital speed keeps it at a great distance from the planet's surface.
In the absence of any other forces, gravitation acts on each portion of the body about equally in a nearly homogeneous gravitational field. The sensation of weightlessness arises when there is no normal force exerted between a body (e.g., an astronaut in orbit) and its surrounding objects, a circumstance that also occurs when the gravitational field is weak (such as when far away from any source of gravity).
The term "free fall" is frequently used in a broader sense than that stated above. Free fall is the term used to describe falling through the atmosphere without the use of a parachute or other lifting device. Because the aerodynamic drag forces prohibit full weightlessness in such scenarios, a skydiver's "free fall" after achieving terminal velocity gives the impression that the body's weight is supported on a cushion of air.

Note: In general relativity, an object in free fall is an inertial body travelling down a geodesic with no force acting on it. The Newtonian theory of free fall fits with general relativity far away from any sources of space-time curvature, where spacetime is flat. Otherwise, they disagree; for example, only general relativity can explain orbital precession, orbital decay or inspiral of compact binaries caused by gravitational waves, and direction relativity (geodetic precession and frame dragging).