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joule
unit of energy measurement
Also known as: J
How is energy defined and measured?Overview of how scientists use the joule unit to measure work or energy.
See all videos for this articlejoule, unit of work or energy in the International System of Units (SI); it is equal to the work done by a force of one newton acting through one metre. Named in honour of the English physicist James Prescott Joule, it equals 107 ergs, or approximately 0.7377 foot-pounds. In electrical terms, the joule equals one watt-second—i.e., the energy released in one second by a current of one ampere through a resistance of one ohm.
The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Adam Augustyn.
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