Question

A box of weight 50 kg rests on the surface of a lift. If the lift begins to fall freely under gravity, what is the force with which the box applies force on the surface?

Answer 1

When the lift is falling freely under gravity, then the box of weight 50 kg kept in it also falls freely under the action of gravity. The reaction force on the surface of the lift on the box is zero. So the action force of the box on the surface of the lift should also be zero. Thus, the box on the surface of the lift exerts no force when the lift is falling freely under gravity.