As an object falls from rest, its gravitational potential energy is converted to kinetic energy. Conservation ofenergy as a tool permits the calculation of the velocity just before it hits the surface. K.E. = J, which is of course equal to its initial potential energy.
Answer ~ As the body falls from height h, its potential energy decreases while the kinetic energy begins to increase; the total mechanical energy at any point being the same i.e. m g h. When the body reaches the ground, P.E. = 0 and K.E. is equal to the initial potential energy m g h at the height h.
I hope this helps! ~ Kana