kinetic energy

American  

[ki-net-ik en-er-jee, kahy-net-ik] / kɪˈnɛt ɪk ˈɛn ər dʒi, kaɪˈnɛt ɪk /

noun

Physics.

1. the energy of a body or a system with respect to the motion of the body or of the particles in the system.

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kinetic energy British  

noun

1.  Ek.   K.   T.   KE.  the energy of motion of a body, equal to the work it would do if it were brought to rest The translational kinetic energy depends on motion through space, and for a rigid body of constant mass is equal to the product of half the mass times the square of the speed. The rotational kinetic energy depends on rotation about an axis, and for a body of constant moment of inertia is equal to the product of half the moment of inertia times the square of the angular velocity. In relativistic physics kinetic energy is equal to the product of the increase of mass caused by motion times the square of the speed of light. The SI unit is the joule but the electronvolt is often used in atomic physics

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kinetic energy Scientific  

/ kə-nĕt′ĭk /

1. The energy possessed by a system or object as a result of its motion. The kinetic energy of objects with mass is dependent upon the velocity and mass of the object, while the energy of waves depends on their velocity, frequency, and amplitude, as well as the density of the medium if there is one (as with ocean waves).

2. Compare potential energy

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kinetic energy Cultural  

1. The energy an object has because of its motion.

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Etymology

Origin of kinetic energy

First recorded in 1865–70

Compare meaning

How does kinetic-energy compare to similar and commonly confused words? Explore the most common comparisons:

• kinetic energy vs. potential energy

Example Sentences

See Examples For:

kinetic energy

In less than four seconds—according to butterflies let loose in my stomach—the Bentley swept past 60 mph, casually acquiring a kinetic energy of nearly one megajoule, roughly equivalent to a stick of dynamite.

From The Wall Street Journal ● Jul. 18, 2026

The 2.4-litre V8s used in 2013 weighed 130kg, including the small kinetic energy recovery systems used then and batteries.

From BBC ● May 14, 2026

The system's kinetic energy stopped increasing and leveled off.

From Science Daily ● Jan. 8, 2026

His novels move with kinetic energy, his plots are intricate puzzles shrouded in religious iconography, ancient cryptography and other obscure arcana.

From Los Angeles Times ● Sep. 9, 2025

But it bristled with Lawrence’s self-confidence and his manner of intuitively grasping possibilities well ahead of realities—in this case, the production of sustained resonant proton beams with a million volts of kinetic energy.

From "Big Science" by Michael Hiltzik