Newton's laws of motion are three
physical laws that, together, laid the foundation for
classical mechanics. They describe the relationship between a body and the
forces acting upon it, and its
motion in response to those forces. They have been expressed in several different ways, over nearly three centuries, and can be summarised as follows. The three laws of motion were first compiled by
Isaac Newton in his
Philosophiæ Naturalis Principia Mathematica (
Mathematical Principles of Natural Philosophy), first published in 1687. Newton used them to explain and investigate the motion of many physical objects and systems. For example, in the third volume of the text, Newton showed that these laws of motion, combined with his
law of universal gravitation, explained
Kepler's laws of planetary motion.