Physics
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Kinetic Energy Calculator.
Calculate classical kinetic energy and momentum from mass and speed.
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Results update as you type.
How to Use
Kinetic energy is KE = ½ × mass × speed². Enter kilograms and metres per second for joules.
This is the classical formula. At speeds close to the speed of light, relativistic mechanics is required.
FAQs
What is the kinetic energy formula?
Classical kinetic energy is KE = ½ × m × v², where m is mass in kilograms and v is speed in metres per second. The result is measured in joules.
What units does this calculator use?
Enter mass in kilograms and speed in metres per second. The calculator returns energy in joules and momentum in kilogram-metres per second.
Does this work at near-light speeds?
No. This tool uses the classical approximation. Relativistic kinetic energy is required when an object's speed is a meaningful fraction of the speed of light.