Question

A boy of mass $m$ climbs up a staircase of vertical height $h$. A girl, of same mass, come up the same vertical height using a lift. Then

• A. work done by the boy is more than work done by the girl
• B. work done by the girl is more than work done by the boy
• C. both of them do the same amount of work
• D. work done by the girl is zero

Answer 1

Answer: (C)

both of them do the same amount of work

On both the cases, work done against gravity = Weight $\times$ vertical displacement = $m\times g\times h$, as both have same mass (and weight) and suffer same vertical displacement. So, both of them do the same amount of work.