Question

Two particles of equal mass go round a circle of radius R under the action of their mutual gravitational attraction. The speed of each particle is

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Centrpetal force provided by the gravitational force of attraction between two particles\

$i.e.\frac{m{v}^2}{R}=\frac{Gm\times m}{(2R{)}^2}$

$\Rightarrow v=\frac{1}{2}\sqrt{\frac{Gm}{R}}$