Question

In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.

Answer 1

In the first case, the force and displacement are perpendicular to each other, so work done is zero. 

In the second case, the force and displacement are in the same direction, so the work done is positive. 

In the third case, the force and displacement are in the opposite direction, so the work done is negative.