Question

When a body falls freely towards the earth, then its total energy
A. First decreases and then becomes zero
B. Remains constant.
C. Increases
D. Decreases

Answer 1

Hint: 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 under general relativity, where gravity is reduced to a space-time curvature. In the technical definition of the phrase "free fall," an item may or may not be falling down in the common sense. Although an item travelling upwards is not generally regarded to be falling, it is said to be in free fall if it is simply subjected to the force of gravity. The Moon is therefore in free fall around the Earth, despite the fact that its orbital speed keeps it at a great distance from the planet's surface.

Complete step by step solution:
In the absence of any other forces, gravity acts on each component of the body nearly equally in a relatively homogeneous gravitational field. The sense of weightlessness arises when there is no normal force exerted between a body and its surrounding objects, a situation that also happens when the gravitational field is weak. When the body is at rest and at a certain height, the energy it possesses is known as potential energy; however, when the body falls freely, its potential energy decreases while its kinetic energy increases. Assuming no energy is lost, the overall energy of the system remains constant at all times. It also possesses entire kinetic energy when it hits the ground. As a result, the body's energy remains constant. The phrase "free fall" is frequently used in a broader sense than that specified 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 true weightlessness in such conditions, 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:
The total of potential and kinetic energy stored or held by a body that is either at rest or in motion is known as mechanical energy. Work is done with mechanical energy. There is also a highly significant theorem known as the work energy theorem. The net work done by forces on an item equals the change in its kinetic energy, according to the work-energy theorem.