If you weigh 690 {rm N} on the earth, what would be your weight on the surface of a neutron star that has the same mass as our sun and a diameter of 21.0 {rm km}?
Take the mass of the sun to be m_s = 1.99×1030 {rm kg}, the gravitational constant to be G = 6.67×10-11 {rm N} cdot {rm m^2/kg^2}, and the acceleration due to gravity at the earth's surface to be g = 9.810 {rm m/s^2}.