Kinetic Energy Calculator
KE = ½mv². Mass and speed in, energy in joules out.
Example — 2 kg moving at 3 m/s9 J
How we got it — the example, step by step
- Kinetic energy = ½ × m × v².
- = ½ × 2 × 3² = ½ × 2 × 9 = 9 J.
Check it backwards
Solve back: √(2 × 9 ÷ 2) = 3 m/s — the speed we started with.
Questions people also ask
Why does doubling speed matter so much?
Because speed is squared: double the speed and the energy is four times as much, not two. That is why stopping distances grow so fast.