Action and reaction

Definition

Action and reaction refer to Newton's third law of motion, stating that for every action (force) exerted by one object on another, there is an equal but opposite reaction (force) exerted by the second object back on the first.

Related terms

Newton's laws of motion: A set of three fundamental principles that describe the relationship between an object and the forces acting upon it.

Momentum:

The product of an object's mass and velocity, which represents its quantity of motion.

Force pair: Two forces that are equal in magnitude but opposite in direction, acting on two different objects in contact with each other.