Question

A particle of mass $m$ is rotating in a plane in circular path of radius $r$. Its angular momentum is $L$. The centripetal force acting on the particle is.

• A. $\frac{L^2}{mr}$
• B. $\frac{L^{2}m}{r}$
• C. $\frac{L^2}{m^2{r}^2}$
• D. $\frac{L^2}{m{r}^3}$

Answer 1

The correct option is D $\frac{L^2}{m{r}^3}$

Centripetal force, $F=\frac{m{v}^2}{r}=\frac{m}{r}\frac{L^2}{m^2{r}^2}=\frac{L^2}{m{r}^3}$

$[As,L=mvr\therefore v=\frac{L}{mr}]$