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Physics

Kinetic Energy Calculator (½mv²)

Translational kinetic energy of a moving body from its mass and speed.

Result

Kinetic Energy (KE)

100 J

In kilojoules

0.1 kJ

Mass

2 kg

Velocity

10 m/s

Concept

Kinetic energy is the energy a body possesses due to its motion. It is a scalar quantity — always non-negative.

The v² dependence means doubling speed quadruples kinetic energy — this is why road speed limits matter so much for crash energy.

Work-Energy theorem: the net work done on a body equals its change in kinetic energy. KE is measured in joules (J = kg·m²/s²).

Formula

KE=12 × m × v2
v=2 × KE ÷ m

Variables

KEJ = kg·m²/s²
Kinetic energy.
mkg
Mass of the body.
vm/s
Speed of the body — use the magnitude of the velocity vector.