The force due to gravity ‘F’ on a body of mass ‘m’ kept on the surface of earth of mass ‘M’ and radius ‘R’, is equal to the force of attraction between the earth and that body.
F = {GMm\over R^2}
The value of G remains the same at all places and it is independent of the nature of the particles, temperature, medium, etc.
Therefore, it is a universal constant and is known as a Universal Gravitational Constant.
