Question

when do you say that work is done ?

Answer 1

If a force is applied but the object doesn't move, no work is done; if a force is applied and the object moves a distance d in a direction other than the direction of the force, less work is done than if the object moves a distance d in the direction of the applied force.

Answer 2

hey...

when a force causes displacement of an object then we can say WORK IS DONE.

Work done = force × displacement.

e.g.

when we push trolley when apply force by push and then causes displacemnt so here WORK is DONE