Question

A thin rod of length $L$ is bent to form a semi circle. The mass of the rod is $M$. What will be the gravitational potential at the centre of the circle?

• A. $\frac{-GM}{L}$
• B. $\frac{-GM}{2\pi L}$
• C. $\frac{-\pi GM}{2L}$
• D. $\frac{-\pi GM}{L}$

Answer 1

The correct option is D $\frac{-\pi GM}{L}$

$L=\pi R⟹R=\frac{L}{\pi }$
$V_c=\frac{-GM}{R}=\frac{-GM}{}\frac{L}{\pi }=\frac{-\pi GM}{L}$