Newton's law of inertia says that the momentum of an object remains constant unless it is acted on by an unbalanced force. The momentum of an object is the product of its mass and velocity. Newton's law of force says that when a force acts on a body, it causes a change in its momentum in the direction in which the force is applied. Newton's law of action and reaction says that when one body exerts a force on a second body, the second body exerts a force on the first equal in magnitude but opposite in direction. Newton's law of universal gravitation states that every two particles of matter attract each other with a force that depends on the product of their masses and varies inversely with the square of the distance between them.
Angular momentum is the momentum associated with rotation or revolution.
Angular momentum can be transferred from one object to another or redistributed. However, it is always conserved. Newton found that orbiting objects attracted to the Sun by the force of gravity obey Kepler's laws. He discovered a general form of Kepler's third law relating the separation, orbital period, and masses of any two orbiting bodies. This relationship is the basis of most astronomical mass determinations.