Answer:
When the force and displacement are at an angle of 90 degrees to each other
Step-by-step explanation:
W = F * d * cos(θ)
Where: W is the work done. F is the force applied. d is the displacement. θ is the angle between the force and the direction of displacement.
If the force and displacement are at an angle of 90 degrees to each other (θ = 90°), the cosine of 90 degrees is zero, which means that the work done (W) will also be zero. In this situation, the force is acting perpendicular to the direction of displacement, and as a result, no work is performed on the object even though there is some displacement.
For example, if you carry a box and walk forward, the work done will be zero because the force you apply (lifting the box vertically) is vertical, while the displacement (your forward motion) is horizontal. The angle θ between the force and displacement is 90 degrees. In this case, the force may cause the box to be lifted, but it doesn't contribute to the box's forward motion, so there's no work performed in the direction of your walking.