Question

Write an expression for the work done when a force is acting on an object in the direction of its displacement.

Answer 1

Step 1:

Work is said to be done when the force applied to an object shows the object’s displacement.

$\Rightarrow$Work done $=$ Force $\times$ Displacement $\times \cos \theta$

Also, since the force vector is in the direction of the displacement vector, the angle between the two vectors will be equal to $0°$.

Step 2: Calculating work done

Let us consider

Force $=F$

Displacement $=S$

Work done $=W$

Then,

$$\begin{gathered} \Rightarrow W=F\times S\times \cos \left(0°\right) \\ \Rightarrow W=F\times S\times 1 \\ \Rightarrow W=FS \end{gathered}$$