Question

A force $F$ acts on a body and displaces it by a distance $S$ in a direction at an angle $\theta$ with the direction of force. Write the expression for the work done by the force.

• A. $F$ $S$ $\sin \theta$
• B. $F$ $S$ $\cot \theta$
• C. $F$ $S$ $\cos \theta$
• D. $F$ $S$ $\tan \theta$

Answer 1

The correct option is C $F$ $S$ $\cos \theta$

Here we are applying a force $F$ at an angle of $\theta$, if we resolve the force it becomes $F\cos \theta$ and $F\sin \theta$.

We have displacement along $F\cos \theta$

We know that work-done is the product of force and displacement along the direction of the force.
Hence,
$workdone=F\cos \theta \ast S$.