Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects. if u look at the definition of force u get "strength or energy as an attribute of physical action or movement." and when you are talking about forces between two objects of a different mass u think of Force equals mass times acceleration [ ]. For every action there is an equal and opposite reaction. Every object in a state of uniform motion will remain in that state of motion unless an external force acts on it.
