Question

A force $\overrightarrow{F}=(5\hat{i}+4\hat{j})N$ acts on a body and produced a displacement $\overrightarrow{S}=(6\hat{i}-5\hat{j}+3\hat{k})m$. The work done will be

• A. $10J$
• B. $20J$
• C. $30J$
• D. $40J$

Answer 1

The correct option is A $10J$

$\overline{W}=\overrightarrow{F}\cdot \overrightarrow{S}$

$=\left(5\hat{i}+4\hat{j}\right).\left(6\hat{i}-5\hat{j}+3\hat{k}\right)$

$=30-20+0$

$=10J$