Two particles of equal mass 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.

Two particles of equal mass move in a circle of radius r under the act

1.	Two particles of equal mass 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.
Answer» Solution : The particle will ALWAYS remain diametrically OPPOSITE , so that the force on each particle will be directed along the radius. When each particle is describing a CIRCULAR orbit, the gravitational force on one of the PARTICLES must be equal to the necessary centripetal force , `(mV^2)/r =(Gmm)/((2r)^2)"" i.e V = sqrt((Gm)/r)`