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 long arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.

Answer 1

i) In the first case force is acting perpendicular to the displacement of the object. So the work done by the force is zero. 

ii) In the second case force is acting in the direction of displacement. So work done by the force is positive. 

iii) In the third case force and displacement opposite to each other. So the work done is negative.