# Newton's laws of motion

**Newton's laws of motion** are three laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows:[1]

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*Law 1*. A body continues in its state of rest, or in uniform motion in a straight line, unless acted upon by a force.

*Law 2*. A body acted upon by a force moves in such a manner that the time rate of change of momentum equals the force.

*Law 3*. If two bodies exert forces on each other, these forces are equal in magnitude and opposite in direction.

The three laws of motion were first stated by Isaac Newton in his *Philosophiæ Naturalis Principia Mathematica* (*Mathematical Principles of Natural Philosophy*), first published in 1687.[2] Newton used them to explain and investigate the motion of many physical objects and systems, which laid the foundation for Newtonian mechanics.[3]