Mechanical equivalent of heat Meaning, Definition & Usage

Definitions
  1. . See under Equivalent.
Definitions
  1. (Physics), the number of units of work which the unit of heat can perform; the mechanical energy which must be expended to raise the temperature of a unit weight of water from 0° C. to 1° C., or from 32° F. to 33° F. The term was introduced by Dr. Mayer of Heilbronn. Its value was found by Joule to be 1390 foot pounds upon the Centigrade, or 772 foot pounds upon the Fahrenheit, thermometric scale, whence it is often called Joule's equivalent, and represented by the symbol J. This is equal to 424 kilogram meters (Centigrade scale). A more recent determination by Professor Rowland gives the value 426.9 kilogram meters, for the latitude of Baltimore.

Webster 1913