Question

A particle of mass $m$ describes a circle of radius $r$ . The centripetal acceleration of the particle is $\frac{4}{r^{2}}$ . The momentum of the particle is

• A. $\frac{4 m}{r}$
• B. $\frac{2 m}{r}$
• C. $ \, \frac{4 m}{\sqrt{r}}$
• D. $ \, \, \frac{2 m}{\sqrt{r}}$

Answer 1

Answer: (D)

Given, centripetal acceleration = $\frac{4}{r^{2}}$
$\therefore \frac{v^{2}}{r}=\frac{4}{r^{2}}$
or $v=\frac{2}{\sqrt{r}}$
Hence, $p=\frac{2 m}{\sqrt{r}}$