Question

A vector $\overrightarrow{V}$ is given in a rectangular coordinate system as $V=4\overrightarrow{i}+3\overrightarrow{j}$
where $\overrightarrow{i}$ and $\overrightarrow{j}$ are unit vectors along $x$ and $y$ axis then the vector which is three times as long as $\overrightarrow{V}$ is

• A. $12\overrightarrow{i}+9\overrightarrow{j}$
• B. $12\overrightarrow{i}+3\overrightarrow{j}$
• C. $4\overrightarrow{i}+9\overrightarrow{j}$
• D. $12\overrightarrow{i}-9\overrightarrow{j}$

Answer 1

The correct option is A $12\overrightarrow{i}+9\overrightarrow{j}$

$\overrightarrow{V}=4\overrightarrow{i}+3\overrightarrow{j}$
then the vector which is three times as long as $\overrightarrow{v}$ is
$3\overrightarrow{V}=12\overrightarrow{i}+9\overrightarrow{j}$