Question

Read the given statement carefully and answer whether work is done or not done, and why ?

A girl climbing a staircase.

Answer 1

1. When a girl is climbing up the stairs, she is applying force in downward direction and the normal reaction force is in the upward direction.
2. Here the displacement is also in the upward direction.
3. Hence the normal reaction and displacement is in the same direction, that means work done by the force is positive.

Hence, a girl climbing a staircase does work as component of force is in the direction of displacement.