mechanical equivalent of heat

noun

1. (in any system of physical units) the number of units of work or energy equal to one unit of heat, as 4.1858 joules, which equals one small calorie.

mechanical equivalent of heat

noun

1. physics a factor for converting units of energy into heat units. It has the value 4.1868 joules per calorie J

Word History and Origins

Origin of mechanical equivalent of heat¹

First recorded in 1835–45

Example Sentences

The number of units of mechanical work equivalent to one unit of heat is generally called the mechanical equivalent of heat, or Joule’s equivalent, and is denoted by the letter J. Its numerical value depends on the units employed for heat and mechanical energy respectively.

From Project Gutenberg

By a simple and ingenious arrangement he succeeded in measuring the mechanical power expended in producing the currents, and deduced the mechanical equivalent of heat and of electrical energy.

From Project Gutenberg

He also showed that there was no appreciable absorption of heat when air was allowed to expand in such a manner as not to develop mechanical power, and he pointed out that the mechanical equivalent of heat could not be satisfactorily deduced from 145 the relations of the specific heats, because the knowledge of the specific heats of gases at that time was of so uncertain a character.

From Project Gutenberg

Is there a mechanical equivalent of electricity as there is a mechanical equivalent of heat?

From Project Gutenberg

This is called the mechanical equivalent of heat, being merely the quantity of heat necessary to do a certain amount of work, but having no relation to the time in which that work was done.

From Project Gutenberg