A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational
force exerted is
1.73Gmm8a2
dF sin θ will get cancelled
∴ d Fnet = dF cos θ = (dm)E cos θ
= (dm) GM√32√a2+(√3a2)2
∴ Fnet = ∫ d Fnet
= √38 Gmma2
mass of the earth m1 = M, Mass of the moon m2 = M81 and distance between earth & moon d = 60R