In physics, there are

equation In mathematics, an equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign . The word ''equation'' and its cognates in other languages may have subtly different meanings; for example, in F ...

s in every field to relate physical quantities to each other and perform calculations. Entire handbooks of equations can only summarize most of the full subject, else are highly specialized within a certain field.

Physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which ...

is derived of formulae only.

General scope

* Variables commonly used in physics *

Continuity equation A continuity equation or transport equation is an equation that describes the transport of some quantity. It is particularly simple and powerful when applied to a conserved quantity, but it can be generalized to apply to any extensive quantity. ...

Constitutive equation In physics and engineering, a constitutive equation or constitutive relation is a relation between two physical quantities (especially kinetic quantities as related to kinematic quantities) that is specific to a material or substance, and ap ...

Defining equation (physics) In physics, defining equations are equations that define new quantities in terms of base quantities. This article uses the current SI system of units, not natural or characteristic units. Description of units and physical quantities Physical ...

Specific scope

* Defining equation (physical chemistry) * List of equations in classical mechanics *

Table of thermodynamic equations This article is a summary of common equations and quantities in thermodynamics (see thermodynamic equations for more elaboration). Definitions Many of the definitions below are also used in the thermodynamics of chemical reactions. General ...

* List of equations in wave theory * List of relativistic equations * List of equations in fluid mechanics *

List of electromagnetism equations This article summarizes equations in the theory of electromagnetism. Definitions Here subscripts ''e'' and ''m'' are used to differ between electric and magnetic charges. The definitions for monopoles are of theoretical interest, although re ...

* List of equations in gravitation * List of photonics equations *

List of equations in quantum mechanics This article summarizes equations in the theory of quantum mechanics. Wavefunctions A fundamental physical constant occurring in quantum mechanics is the Planck constant, ''h''. A common abbreviation is , also known as the ''reduced Planck cons ...

List of equations in nuclear and particle physics This article summarizes equations in the theory of nuclear physics and particle physics. Definitions Equations Nuclear structure Nuclear decay Nuclear scattering theory The following apply for the nuclear reaction: :''a'' + ''b'' ...

Units and nomenclature

Physical constant A physical constant, sometimes fundamental physical constant or universal constant, is a physical quantity that is generally believed to be both universal in nature and have constant value in time. It is contrasted with a mathematical constant ...

* Physical quantity * SI units * SI derived unit * SI electromagnetism units * List of common physics notations {{DEFAULTSORT:Physics equations

General scope

Specific scope

See also

Units and nomenclature