Newton’s Law of Gravitation

This states that two particles of mass M and mare mutually attracted with equal and opposite forces F and F (see  fig.  )  of  magnitude   F given by the formula

 r = distance between the two particles   

G = universal constant called the constant of gravitation

Newton’s law of gravitation introduces the idea of an action exerted at a distance and extends the range of application of Newton’s third law: the action Fand the reaction 2 F in  above Fig   are equal and opposite, and they have the same line of action.