Two identical spheres each of mass M and radius R are separated by a distance 3R. The force of attraction between them is proportional to

Two identical spheres each of mass M and Radius R are separated by a distance 10R. The gravitational force on mass m placed at the midpoint of the line joining the centres of the spheres is

Two identical spheres each of mass M and Radius R are separated by a distance 10R. The gravitational force on mass m placed at the midpoint of the line joining the centres of the spheres is

Two spheres of equal radius r are touching each other. The force of attra tion between them is proportional to

Two spheres each of mass M and radius R are separated by a distance of r . The gravitational potential at the potential at the midpoint of the line joining the centres of the spheres is

Two spheres each of mass M and radius R are separated by a distance of r . The gravitational potential at the midpoint of the line joining the centres of the spheres is

Two spheres each of mass M and radius R are separated by a distance of r . The gravitational potential at the midpoint of the line joining the centres of the spheres is

The centres of a ring of mass m and a sphere of mass M of equal radius R , are at a distance sqrt(8) R apart as shown. The force of attraction between the ring and the sphere is