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

Options

A. `v=sqrt((1)/(GM))`
B. `v=sqrt((4GM)/(R))`
C. `v=(1)/(2)sqrt((GM)/(R))`
D. `v=(1)/(2R)sqrt((1)/(GM))`

Answer

C

Explanation

Centripetal force is provided by the gravitational force of attraction between two particles.
i.e., `(mv^2)/(R)=(GMxxm)/((2R)^(2))`
`rArrv=(1)/(2)sqrt((GM)/(R))`