Laws of Physical Motion

“Newton's Laws Of Motion Bodies of matter do not alter their motions in any way except as the result of forces applied to them. A body at rest remains at rest, or if in motion, it continues to move in the same direction with the same speed, unless a force is impressed upon it. The second Law is made up of two different parts; A) When different forces are allowed to act upon free bodies, the rates at which the momentum changes are proportional to the forces applied. B) The direction of the change in momentum by a force is that of line of action of the force. The third Law is the Law that asserts the equality of "action" and the "reaction". That is to say, that each action has its equal and opposite reaction.”