Three identical bodies of equal mass m each moves along a circle of radius .R under the action of their mutual gravitational attraction. The speed of each body is

Due to mutual attraction, let every body is moving with a velocity v.From figure, AD=32Ror Lsin⁡60∘=32R  or  L=32R×23=3RCentripetal force on an one mass M is2GM2L2cos⁡60∘/2=Mv2R2GM2L2×32=Mv2R or GM(3R)2×3=v2R∴ V=GM3R