Force is directly proportional to the magnitude of the net force, in the same direction as the net force and it is inversely proportional to the mass of the object. Thus , if the mass of the body is increased then the force between them increases and when the distance between them increase the force decreases now to remove the sign of proportionality we need a constant and that constant is the universal gravitational constant with the value of 6.67 into 10 to the power -11 .