Q27 A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down with an uniform speed of 7 m s ^{-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 your answer be different if the elevator were stationary?

Answers (1)
D Devendra Khairwa

In this case, the heat produced is the loss in the potential energy.


heat produced  =  mg h

or                                            =\ 0.3\times 9.8\times 3

or                                            =\ 8.82\ J

The heat produced (when the lift is stationary) will remain the same as the relative velocity of the bolt with respect lift still remains zero.