In science, work quantifies the measure of the "dynamic effect" of a motor or the action of the movement of a body under the influence of a force. [1] The term was first described as "motive power" in 1824 by French physicist Sadi Carnot to quantify the "effect that a motor is capable of producing", including such effects as to lift water or ore out of mines, impel ships, excavate ports and rivers, forge iron, fashion wood, grind grains, spin and weave cloth, or transport heavy burdens, etc.; each of which can be likened to the measure of the energy associated with the lifting of a weight through a gravitational height. [2]

Force
In the 1687 publication The Mathematical Principles of Natural Philosophy (The Principia), English physicist Isaac Newton outlined the laws governing the relationship between the motions of bodies and force. In simplified form, Newton’s three laws of motion state that:

• A body will stay at rest or continue at constant motion unless acted on by an external force.
• The force acting on an object is equal to the product of the mass of the object and its acceleration.
• Every action has an equal and opposite reaction.

Motive Power
In the 1824 publication Reflections on the Motive Power of Fire, French physicist Sadi Carnot, a former student (1812-14) of the École Polytechnique, defined the term "motive power", what we now understand as work, as: "the effect that a motor is capable of producing", which can be likened to "the elevation of a weight to a certain height", having a measure of "the product of the weight multiplied by the height to which it is raised". [2] The units of the term weight (mg), however, were not clarified at this point by Carnot.

Coriolis
The actual term “work” as the product of force and distance, was coined by French mathematician and engineer Gustave Coriolis in the 1829 textbook Calcul de l'Effet des Machines ("Calculation of the Effect of Machines"). [3] Coriolis, a former student (1808) and later tutor (1816) at the École Polytechnique, may have adopted his logic on that outlined earlier by Carnot.

In any event, French engineer and mathematician Jean-Victor Poncelet, the commandant general of the École Polytechnique, acknowledged that the word “work” was brought in by Coriolis. [4] Poncelet, who in 1824 had become professor of 'mechanics applied to machines', built on the logic of Coriolis and lectured successfully on the topic of work done by machines, wherein he used the word 'travail' to signify work. [6]

Dynamode
Coriolis proposed a unit of work, namely the 'dynamode'. The unit represents 1000 kilogram-metres and was proposed by Coriolis as a measure which could provide a sensible unit with which to measure the work which a person might do, a horse, or a steam engine. Although his term 'work' has become standard, the dynamode did not prove popular in the long run as the unit of work. [4] The use of the kilogram-meter, however, was used by German physicist Rudolf Clausius, in his Mechanical Theory of Heat, beginning in 1850, through 1875. [1]

Pressure-volume work
The graphical measure of work was identified in 1834 by French mining engineer Émile Clapeyron who 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. [5] Specifically, in 1796, Scottish instrument maker James Watt and his employee John Southern developed a work measurement tool called an "indicator diagram", used to exactly quantify the work produced by a steam engine, which made a chart of the pressure of the steam in a cylinder plotted out against the steam's volume:



From this, as was determined by Clapeyron, the work of the steam can be determined using calculus:

Mechanical work
Beginning in 1850, Clausius built on these foundations by digging into the nature of atomic work, in the working substance, using the logic that: [1


He used the terms "motive power", "work", and "mechanical work" somewhat interchangeably; although tending towards the latter terminology in his later papers.

Human molecular work
In human molecular interaction terms, i.e. with reference to human occupational work, the definition is the same, namely any activity energetically equivalent to lifting a weight. The exact quantification of this measurement, e.g. when trying, for instance, to measure "household work" or "child raising work" as compared the work spent in lifting buckets of water up a well, is a major area of research in human thermodynamics. This is where the development of human indicator diagrams are needed.

References
1. (a) Clausius, Rudolf. (1879). The Mechanical Theory of Heat, (pg. 1), (2nd ed). London: Macmillan & Co.
(b) Bennett, Joseph. (1858). A Treatise on Hydraulics, (pg. 316). London: D. Van nostrand.
2. (a) Quote: "we use here motive power (work) to express the useful effect that a motor is capable of producing. This effect can always be likened to the elevation of a weight to a certain height. It has, as we know, as a measure, the product of the weight multiplied by the height to which it is raised."
(b) Carnot, Sadi. (1824). “Reflections on the Motive Power of Fire and on Machines Fitted to Develop that Power.” Paris: Chez Bachelier, Libraire, Quai Des Augustins, No. 55.
(c) Stoner, Clinton D. (2000). "Inquiries into the Nature of Free Energy and Entropy in Respect to Biochemical Thermodynamics." Entropy 2 (3) pgs. 106-141.
3. (a) Jammer, Max (1957). Concepts of Force, (pg. 167). Dover Publications, Inc.
(b) Holtzapple, Mark, T. and Reece, Dan W. (2002). Foundations of Engineering, (pg. 312). McGraw-Hill.
4. (a) Coriolis Biography – MacTutor History of Mathematics Archive.
(b) O I Franksen, “The virtual work principle - a unifying systems concept”, in Structures and operations in engineering and management systems, Trondheim, 1980 (Trondheim, 1981), 17-152.
(c) The contribution of Coriolis, Poncelet, and Navier to the the concept of “work” is examined in detail in: Grattan-Guinness, I. (1984). “Work for the workers : advances in engineering mechanics and instruction in France, 1800-1830, Ann. of Sci. 41 (1), 1-33.
5. 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).
6. Laider, Keith J. (1993). The World of Physical Chemistry, (pg. 77). Oxford University Press.