An object with a mass of 3 kg is dropped from the top of a building. Before it strikes the ground, the object’s speed is 11 m/s.

Question

What was its gravitational potential energy (relative to the ground) the instant the object was dropped? Neglect friction.

Answer 1

Well assuming conservation of mechanical energy (no loss of energy due to air resistance) kinetic energy on ground = GPE when object was dropped

So GPE = 1/2 mv² = 0.5 x 3 x 11² J