Question

A body of a mass 3kg is dropped from the height 1m . The kinetic energy of the body will be when its touchs the ground

Answer 1

Kinetic energy = $m = 3 kg \\h = 1 m$

By law of conservation of energy, we know that maximum potential energy = maximum kinetic energy \\

Hence, Kinetic Energy = Potential Energy = mgh

Let g be 10.

mgh = 3*10*1 = 30 joules

Hope this helps!

Hmu if you have any other doubts. I'd love to clarify!