Three uniform sphere of mass M and radius R each are kept in such a way that each touches the other two. The magnitude of the gravitational force on any of the sphere due to the other two is
Force between two spheres will be
F1=F2=GMM(2R)2=GM24R2
Two forces of equal magnitude are acting at angle 60o on any of the sphere
Fnet=√F21+F22+2F1F2cos60o=F√3
Fnet=√34GM2R2
.Hence, magnitude of force is Fnet=√34GM2R2