Question

In each of the adjoining diagram, 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 first angle b/w f&s is 90°so work done=0
in second angle b/w f&s is 0° so work done is positive
in third angle b/w f&s is 180° so work done is negative

Answer 2

Answer:

(i) In first (extreme left side) figure, the force is acting in a direction perpendicular to

displacement, Hence, work done by the force is zero.

(ii) In second figure, force and displacement both are in same direction. So, the work done by

the force is positive.

(iii) In third (extreme right side) figure, the force and displacement are in mutually opposite

directions, hence, the work done by the force is negative.