Show that the gravitational potential at a point, distance r from the mass M is given by V =-(GM/r)

Two masses 800 kg and 600 kg are at a distance of 0.25 m apart. Calculate the gravitational potential at a point distant 0.02 m from 800 kg mass and 0.15 m from 600 kg mass. G=6.67xx10^(-11)N*m^2*kg^(-1) .

Statement I : Due to an infinitely long linear charge distribution, potential at any point at a distance r from the line is proportional to log r. Statement II : E prop 1/r and E = -(dV)/(dr) .

What will be the gravitational potential on the surface of a planet of mass M and radius R ?

Two small but heavy spheres of mass M each are kept at a distance r on a horizontal plane. The magnitude of the gravitational potential at the mid-point of the line joining the centres of the two spheres will be

The radius of a uniform sphere is R and its mass is M. The values of the gravitational intensity at distance r_1 and r_2 from the centre of the sphere are F_1 and F_2 respectively. Then,

Show that the velocity of a body released at distance r from the centre of the earth, when it strikes the surface of the earth is given by , v=sqrt(2GM(1/R-1/r)) where R and M are the radius and mass of the earth. Also show that the velocity with which meteorites strike the earth's surface is equal to escape velocity.