Show that when a body is dropped from a certain height, the sum of its kinetic energy at any instant during its fall is constant.
Answer:
The mechanical energy (kinetic energy + potential energy) of a freely falling object remains constant. It may be shown by calculation as follows:
Suppose a body of mass m falls from point A, which is at height ‘H’ from the surface of earth. Initially at point A, kinetic energy is zero and the body has only potential energy.
