Question

Give three situations in which a force produces displacement but still, the work done by the force is zero.

Answer 1

Reason for work done to be zero:

1. Work done by the force would be zero while the force and displacement are perpendicular to each other.
2. This results in the $\theta$ value being $90°$and the value of $\cos 90°=0$ and eventually results in the work done being zero.

Possible situations:

1. While a person walks horizontally carrying a briefcase in his hand.
2. Work done by the pull of the sun on earth as the displacement and force are perpendicular to each other.
3. Work done by a coolie carrying luggage on his head.