A body is falling under gravity from rest. When it loses gravitational potential energy by U, its speed is v. The mass of the body shall be
Show that the sum of kinetic energy and potential energy(i.e., total mechanical energy) is always conserved in the case of freely falling body under gravity (with air resistance neglected) from a height h by finding it when (i) the body is at the top, (ii) the body has fallen a distance x, (iii) the body has reached the ground.