joule

¹ American  

[jool, joul] / dʒul, dʒaʊl /

noun

Physics.

1. the standard unit of work or energy in the International System of Units (SI), equal to the work done by a force of one newton when its point of application moves through a distance of one meter in the direction of the force: equivalent to 10 7 ergs and one watt-second. J, j

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Joule ² American  

[jool, joul] / dʒul, dʒaʊl /

noun

1. James Prescott, 1818–89, English physicist.

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Joule ¹ British  

/ dʒuːl /

noun

1. James Prescott. 1818–89, English physicist, who evaluated the mechanical equivalent of heat and contributed to the study of heat and electricity

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joule ² British  

/ dʒuːl /

noun

1.  J.  the derived SI unit of work or energy; the work done when the point of application of a force of 1 newton is displaced through a distance of 1 metre in the direction of the force. 1 joule is equivalent to 1 watt-second, 10 ⁷ ergs, 0.2390 calories, or 0.738 foot-pound

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Joule ¹ Scientific  

1. British physicist who demonstrated that heat is a form of energy. His work established the law of conservation of energy, stating that energy is never destroyed but may be converted from one form into another. The joule unit of energy is named for him.

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joule ² Scientific  

/ jo̅o̅l,joul /

1. The SI derived unit used to measure energy or work. One joule is equal to the energy used to accelerate a body with a mass of one kilogram using one newton of force over a distance of one meter. One joule is also equivalent to one watt-second.

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Etymology

Origin of joule

First recorded in 1885–90; named after J. P. Joule

Explanation

Use the scientific term joule for talking about work, energy, or heat. One joule is equal to the work it takes to make a watt of power for a second, or to move a body one meter with a one-Newton force. In physics, it's common to talk about joules of energy — one example used to illustrate a joule is lifting an apple, which weighs about one Newton. If you raise the apple one meter in the air, you've used one joule of work. The word joule comes from the English physicist James Prescott Joule, who studied the relationship between heat and mechanical work, research that led to the First Law of Thermodynamics.

Example Sentences

However, in an interesting twist, scientists also found that cooking with a smaller flame produced more benzene per joule of gas consumed.

From Los Angeles Times • Jun. 21, 2023

Its value depends on ambient temperature: in your living room, one Landauer would be around 10–21 joule.

From Scientific American • Mar. 29, 2022

Your population would have ample living area on or inside the platforms; meanwhile, through solar power, you’d be able to capture every joule of energy radiating from your star.

From The New Yorker • Oct. 3, 2019

One joule is equivalent to 1 kg m2/s2, which is also called 1 newton–meter.

From Textbooks • Feb. 14, 2019

They had discovered the X ray, the cathode ray, the electron, and radioactivity, invented the ohm, the watt, the Kelvin, the joule, the amp, and the little erg.

From "A Short History of Nearly Everything" by Bill Bryson