Question

what should be the angle between the direction of force and direction of motion of a body so that the work done is zero? give two examples.

Answer 1

the angle between direction of force and displacement should be cos 90 and cos90 is zero .
eg when we pushes a wall the wall does not move so the work done is zero .

Answer 2

Explanation:

angle should be 90° between the direction of force and the direction of motion of a body as work done is equal to force multiplied by displacement multiplied by cosx. and here X=90° so cos90°= 0 so the overall work done will be zero.