Question

when do you say work is not done​

Answer 1

Answer:

Explanation:

W = F*d = Fdcosθ

so W=0 when either net force F=0 or displacement d=0 or Force and displacement are perpendicular to each other (cosθ=0).

Answer 2

Answer:

Explanation:

We say work is not done when displacement or applied is zero.

Also W.D=F.d cosθ

So,when theta is 90 W.D becomes zero