- The International System unit of electrical, mechanical, and thermal energy.
- A unit of electrical energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second.
- A unit of energy equal to the work done when a force of one newton acts through a distance of one meter.
- A practical unit of work or energy equal to 107 ergs, 0.10197 + kilogram-meters, 0.2388+ calories, or 0.7376+ foot-pounds. It was formally adopted as a unit by the international Congress in Chicago (1893) and was legalized in the United States in 1894.
- An electrical unit proposed by Siemens.
- A unit of work which is equal to 107 ergs (the unit of work in the C. G. S. system of units), and is equivalent to one watt-second, the energy expended in one second by an electric current of one ampere in a resistance of one ohm; also called the <altname>absolute joule</altname>. It is abbreviated J or j. The <stype>international joule</stype> is slightly larger, being 1.000167 times the absolute joule. The absolute <ex>joule</ex> is approximately equal to 0.737562 foot pounds, 0.239006 gram-calories (small calories), and 3.72506 x 10-7 horsepower-hours, and 0.000948451 B.t.u.
- See under <er>Equivalent</er>, n.
- In the <xref>International System of Units</xref>, the <xref>derived unit</xref> of <xref>energy</xref>, <xref>work</xref> and <xref>heat</xref>; the work required to <xref>exert</xref> a <xref>force</xref> of one <xref>newton</xref> for a <xref>distance</xref> of one <xref>metre</xref>. Also equal to the energy of one <xref>watt</xref> of power for a duration of one <xref>second</xref>. Symbol: <xref>J</xref>
- a unit of electrical energy equal to the work done when a current of one ampere passes through a resistance of one ohm for one second
- English physicist who established the mechanical theory of heat and discovered the first law of thermodynamics (1818-1889)