Question

A particle moves from $(1,0,3)$ to the point $(-3,4,5)$, when a force $\overline{F}=(\hat{i}+5\hat{k})$ acts on it. Amount of workdone in Joules is

• A. $14$
• B. $10$
• C. $6$
• D. $15$

Answer 1

Answer: (C)

$6$

Here , $\overrightarrow{F}=(\hat{i}+5\hat{k})$

As particle moves from point $(1,0,3)$ to point $(-3,4,5)$ , therefore displacement of particle

$\overrightarrow{d}=(-3\hat{i}+4\hat{j}+5\hat{k})-(\hat{i}+3\hat{k})=(-4\hat{i}+4\hat{j}+2\hat{k})$

$W=?$

As $W=\overrightarrow{F}.\overrightarrow{d}$

Therefore $W=(\hat{i}+5\hat{k}).(-4\hat{i}+4\hat{j}+2\hat{k})=-4+10=6J$