Question

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

• A. $2\frac{m}{r}$
• B. $2\frac{m}{\sqrt{r}}$
• C. $4\frac{m}{\sqrt{r}}$
• D. None of these

Answer 1

The correct option is B $2\frac{m}{\sqrt{r}}$

Centripetal acceleration $a_c=\frac{v^2}{r}$

Thus $\frac{4}{r^2}=\frac{v^2}{r}$

$⟹v=\frac{2}{\sqrt{r}}$

Momentum $P=mv=m\frac{2}{\sqrt{r}}$