Mass density of a solid sphere is ρ. Radius of the sphere is R. The gravitational field at distance r from the centre of the sphere inside it is
The density inside a solid sphere of radius a is given by ρ =ρ0a/r where ρ0 is the density at the surface and r denotes the distance from the centre. The gravitational field due to this sphere at a distance 2a form its centre is..