question_answer 27)

A bolt of mass 0.3 kg falls from the ceiling of an elevator moving down with a uniform speed of . It hit the floor of the elevator (length of the elevator 3 m) and does no rebound. What is the heat produced by the impact ? Would you answer be different, if the elevator were stationary ?  

Answer:

As the elevator is moving down with a uniforn speed (a = 0), so the value of g remains the same. Here P.E. lost by the bolt As the bolt does not rebound, the energy is converted into heat.  Heat produced = 8.82 J Even if the elevator were stationary, the same amount of heat would have produced because the value of g is same in all inertial frames of reference.