- James P., British physicist, 1818–1889. See j., J. equivalent.
* * *joule 'jü(ə)l n a unit of work or energy equal to the work done by a force of one newton acting through a distance of one meterJoule James Prescott (1818-1889)British physicist. Joule is famous for his experiments on heat. In a series of investigations he demonstrated that heat is a form of energy (regardless of the substance that is heated) and later determined quantitatively the amount of mechanical and electrical energy expended in the generation of heat energy. In 1843 he published his value for the amount of work required to produce a unit of heat, now known as the mechanical equivalent of heat. He established the principle that various forms of energy-mechanical, electrical, and heat-are basically the same and are interchangeable. This principle forms the basis of conservation of energy. The joule unit of work or energy was named in his honor in 1882.
* * *n.the SI units of work or energy, equal to 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. In electrical terms the joule is the work done per second when a current of 1 ampere flows through a resistance of 1 ohm. Symbol: J. See also calorie.
* * *(J) (jl) [James Prescott Joule, English physicist, 1818â€“1889] the SI unit of quantity of energy, being the work done by a force of 1 newton acting over a distance of 1 meter in the direction of the force.
Medical dictionary. 2011.