Newton second law

Laws in physics about force and motion

"Newton's laws" redirects here. For other uses, see Newton's law.

"F=ma" redirects here. For the physics competition, see F=ma exam.

Newton's laws of motion are three physical laws that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows:

1. A body remains at rest, or in motion at a constant speed in a straight line, except insofar as it is acted upon by a force.
2. At any instant of time, the net force on a body is equal to the body's acceleration multiplied by its mass or, equivalently, the rate at which the body's momentum is changing with time.
3. If two bodies exert forces on each other, these forces have the same magnitude but opposite directions.^[1][2]

The three laws of motion were first stated by Isaac Newton in his Philosophiæ Naturalis Principia Mathematica Sir isaac newton law of gravity.