Question

If a object of mass m is dropped from rest from a height h in free fall motion, what is the kinetic energy when it is a height h/4 above the ground?

Answer 1

we have v ^2 - u^2 = 2gh

at height h/4   v^2 = 2 g h/4         (freely falling u = 0)

                                = gh/2

kinetic energy K = 1/2 mv^2

                             1/2 m (gh/2)

                           = mgh/4