In thermodynamics, mechanical work W is measure of the energy exerted whenever a body moves under the influence of a force. Specifically, if a force F acts on a single material point, causing it to move in a given direction, the product of the force and the distance d moved through is the “mechanical work” which the force performs during the motion: [1]

W = F∙d

The etymology of the term mechanical work seems to stem from the writings of French engineer Sadi Carnot. In 1824, Carnot outlined the view that "already the steam-engine works our mine" and used the expression "motive power", which he used synonymously with the term impelling power, to quantify the useful effect of that a motor is capable of producing as “the product of the weight multiplied by the height to which it is raised.” [2] In 1834, French engineer Émile Clapeyron used the phrase “mechanical action” as “the integral of the product of the pressure times the differential of the volume” during either the expansion or contraction of the gas and the resultant piston movement. [3] In 1850, German physicist Rudolf Clausius began to use the terms "motive power", "work", and "mechanical work" somewhat interchangeably; although tending towards the latter terminology in his later papers. [4]

1. Clausius, Rudolf. (1879). The Mechanical Theory of Heat (pg. 1), (2nd ed.). London: Macmillan & Co.
2. Carnot, Sadi. (1824). “Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power.” (pg. 5). Paris: Chez Bachelier, Libraire, Quai Des Augustins, No. 55.
3. Clapeyron, Émile. (1834). “Memoir on the Motive Power of Heat”, Journal de l’Ecole Polytechnique. XIV, 153 (and Poggendorff's Annalender Physick, LIX, [1843] 446, 566).
4. Clausius, Rudolf. (1850). "On the Motive Power of Heat, and on the Laws Which can be Deduced From it for the Theory of Heat." Poggendorff's Annalen der Physik, LXXIX, 368, 500.

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