Two particles of equal mass `'m'` go around a circle of radius `R` under the action of their mutual gravitaitonal attraction. The speed of each particle with respect to their centre of a mass is -

Options

A. `sqrt(Gm)/(R )`
B. `sqrt(Gm)/(4R )`
C. `sqrt(Gm)/(3 R)`
D. `sqrt(Gm)/(2R )`

Answer

B

Explanation

Gravitatinal force provides necessary centripetal force

`(Gm^(2))/(2R)^(2)=(mv^(2))/(R ) rarr V=sqrt(Gm)/(4R)`