Question

A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down with an uniform speed of 7 ms^-1. It hits the floor of the elevator (length of the elevator = 3 m) and does not rebound. What is the heat produced by the impact? Would you answer be different if the elevator were stationary?

Answer 1

Potential energy of bolt = mgh = 0.3 x 9.8 x 8.82 J

The bolt does not rebound. Therefore, the whole of the energy is converted into heat. Since the value of acceleration due to gravity is the same in all inertial systems, therefore, the answer will not change even if the elevator is stationary.