Three uniform spheres each having a mass M and radius a are kept in such a way that each touches the other two. Find the magnitude of the gravitational force on any of the spheres due to the other two.

Explanation

`F_(0)=(G.M.M)/((2a)^(2))=(GM^(2))/(4a^(2))`
Resultant force on `M`
`F=2F_(0)cos30^(@)=sqrt(3)F_(0)=(sqrt(3)GM^(2))/(4a^(2))`