Form of energy that an object has by reason of its motion. The kind of motion may be translation (motion along a path from one place to another), rotation about an axis, vibration, or any combination of motions. The total kinetic energy of a body or system is equal to the sum of the kinetic energies resulting from each type of motion. The kinetic energy of an object depends on its mass and velocity. For instance, the amount of kinetic energy math.Kmath.E of an object in translational motion is equal to one-half the product of its mass math.m and the square of its velocity math.v, or math.Kmath.E = 12math.mmath.v², provided the speed is low relative to the speed of light. At higher speeds, relativity changes the relationship.

Learn more about kinetic energy with a free trial on Britannica.com.