Physics - Gravitation Question with Solution | TestHub

Let speed of both the particles be $v$.

Then, gravitational force between the particles will provide the required centripetal force.

Therefore,

$\frac{G\left(m\right)\left(m\right)}{{\left(2r\right)}^2}=\frac{m{v}^2}{r}$

$\Rightarrow v=\sqrt{\frac{Gm}{4r}}$