Newton's laws of motion consist of three physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motiondue to those forces. They have been expressed in several different ways over nearly three centuries, and can be summarized as follows:
- First law: Every body remains in a state of rest or uniform motion (constant velocity) unless it is acted upon by an external unbalanced force. This means that in the absence of a non-zero net force, the center of mass of a body either remains at rest, or moves at a constant speed in a straight line.
