law of motion

[law uhv moh-shuhn]

noun

Physics.

1. any of three laws of classical mechanics, either the law that a body remains at rest or in motion with a constant velocity unless an external force acts on the body first law of motion, the law that the sum of the forces acting on a body is equal to the product of the mass of the body and the acceleration produced by the forces, with motion in the direction of the resultant of the forces second law of motion, or the law that for every force acting on a body, the body exerts a force having equal magnitude and the opposite direction along the same line of action as the original force third law of motion, or law of action and reaction.

Word History and Origins

Origin of law of motion¹

First recorded in 1660–70

Example Sentences

The fundamental law of motion of cybernetics is that if you have a control system, it has to have at least as much complexity as the thing it's trying to control.

From Salon

To join the known physics laws of thermodynamics, electromagnetism and Newton’s laws of motion and gravity, the nine scientists and philosophers behind the paper propose their “law of increasing functional information.”

From Salon

The first law of motion is often paraphrased as “objects in motion tend to stay in motion, and objects at rest tend to stay at rest.”

From Scientific American

This is consistent with Aristotle’s debunked theory of physics, which did not account for the effects of Newton’s first law of motion.

From Scientific American

No amount of word salad can repeal Isaac Newton’s second law of motion, F=ma.

From Washington Post