Question

A particle is moving with speed $6m/s$ along the direction of $\overrightarrow{A}=2\hat{i}+2\hat{j}-\hat{k}$, find the velocity (in $m/s$).

• A. $(4\hat{i}+4\hat{j}-2\hat{k})$
• B. $(2\hat{i}+2\hat{j}-\hat{k})$
• C. $(8\hat{i}+8\hat{j}-4\hat{k})$
• D. $(\hat{i}+\hat{j}-\hat{k})$

Answer 1

The correct option is A $(4\hat{i}+4\hat{j}-2\hat{k})$

Velocity = (speed) $\hat{A}$
$=6\times \frac{(2\hat{i}+2\hat{j}-\hat{k})}{\sqrt{4+4+1}}$
Velocity $=(4\hat{i}+4\hat{j}-2\hat{k})m/s$