alleryWork done by a force on a body is negative when:
Aforce is perpendicular to displacement
Bforce is in the same direction as displacement
Cforce acts opposite to the displacement
Dthere is no displacement
Answer & Solution
Correct answer: C. force acts opposite to the displacement
Since $W=Fs\cos\theta$, work is negative when the angle between force and displacement is greater than $90^\circ$.
In the standard case of opposite directions, $\theta=180^\circ$, so the work is negative.
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