Question

In which case work is not done:

• A. a girl swimming in a pond
• B. a windmill lifting water from a well
• C. a standing man holding a suit case in his hand
• D. a sail boat moving in the direction of wind

Answer 1

The correct option is C

a standing man holding a suit case in his hand

1. No work is done, when a force acts at right angles to the direction of displacement.
2. It is because in such a situation, displacement in the direction of force is zero.

Hence, the correct answer is option (C) i.e. a standing man holding a suit case in his hand