Two particles of equal masses move in a circle of radius r under the action of their mutual gravitational attraction. Find the speed of each particle if its mass is m

Explanation

The particles will always remain diametrically opposite so that the force on each particle will be directed along the radius . Considering the circulation of one particle, we have
`(mv^(2))/(r) = (G m m)/( (2 r)^(2)) , ` i.e., `v = sqrt((Gm)/(4 r))`