Question

show that the mechanical energy of a freely falling body is constant

Answer 1

As, mechanical energy= P.E + K.E. A freely faaling body has only a gravitational force . So, it provide a constant acceleration to the body and hence their energy didn't chnge.

Answer 2

Answer:

It may be shown that in the absence of external frictional force the total mechanical energy of a body remains constant. ... Thus we have seen that sum of potential and kinetic energy of freely falling body at all points remains same. Under the force of gravity, the mechanical energy of a body remains constant.