Question

A porter carrying a load on his head on a horizontal road does no work against Gravity.

• A. True
• B. False

Answer 1

The correct option is A True

Work done by any force is given by dot product of force and displacement of the particle.

So $W=F.S$

Where $F,S$ are vector quantities and $W$ is scaler quantity.

SI Unit of work done is $N.m$ and also called $Joule\left(J\right)$.

So work done in above case is $W=FSCos\theta$, here $\theta ={90}^{\circ }$

Because person moves horizontal and force of gravity is vertical.

So work done is Zero.

Hence above statement is true