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

Explanation

For the circular motion of each particle, `(mv^(2))/r=(Gm m)/((2r)^(2)) implies v^(2) = (Gm)/(4r) implies v=1/2 sqrt((Gm)/r)`.