Question

A body of mass $1kg$ is moving with a velocity $\overrightarrow{v}=(10\hat{i}+5\hat{j})m/s.$ What is the angle made by the momentum vector with x-axis?

• A. ${\tan }^{-1}\left(\frac{1}{2}\right)$
• B. ${\tan }^{-1}\left(\frac{1}{4}\right)$
• C. ${\tan }^{-1}2$
• D. ${\cot }^{-1}\left(\frac{1}{2}\right)$

Answer 1

The correct option is A ${\tan }^{-1}\left(\frac{1}{2}\right)$


$\overrightarrow{p}=m\overrightarrow{v}=10\hat{i}+5\hat{j}$;
$\tan \theta =\frac{y}{x}=\frac{5}{10}=\frac{1}{2}$
$\Rightarrow \theta ={\tan }^{-1}\left(\frac{1}{2}\right)$