Fundamental Thermodynamic Relation

In thermodynamics, the fundamental thermodynamic relation is generally expressed as an infinitesimal change in internal energy in terms of infinitesimal changes in entropy, and volume for a closed system in thermal equilibrium in the following way.

Here, U is internal energy, T is absolute temperature, S is entropy, P is pressure, and V is volume.

This is only one expression of the fundamental thermodynamic relation. It may be expressed in other ways, using different variables (e.g. using thermodynamic potentials). For example, the fundamental relation may be expressed in terms of the Helmholtz free energy (F) as:

Read more about Fundamental Thermodynamic Relation:  Derivation From The First and Second Laws of Thermodynamics, Derivation From Statistical Mechanical Principles

Famous quotes containing the words fundamental and/or relation:

    Each [side in this war] looked for an easier triumph, and a result less fundamental and astounding. Both read the same Bible, and pray to the same God; and each invokes His aid against the other. It may seem strange that any men should dare to ask a just God’s assistance in wringing their bread from the sweat of other men’s faces; but let us judge not that we be not judged.
    Abraham Lincoln (1809–1865)

    [Man’s] life consists in a relation with all things: stone, earth, trees, flowers, water, insects, fishes, birds, creatures, sun, rainbow, children, women, other men. But his greatest and final relation is with the sun.
    —D.H. (David Herbert)