Question

How much energy is gained by a box of mass $20kg$ when a man carrying the box waits for $5$ minutes for a bus? $(g=10m{s}^{-2})$

Answer 1

When a man holds a box for a certain mount of time, no energy is being transferred to it, as the gain/loss in kinetic energy or potential energy by the box is zero. Here the box does not have any displacement, so no work is done on it.