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List Of Equations In Wave Theory
This article summarizes equations in the theory of waves. Definitions General fundamental quantities A wave can be longitudinal where the oscillations are parallel (or antiparallel) to the propagation direction, or transverse where the oscillations are perpendicular to the propagation direction. These oscillations are characterized by a periodically time-varying displacement in the parallel or perpendicular direction, and so the instantaneous velocity and acceleration are also periodic and time varying in these directions. (the apparent motion of the wave due to the successive oscillations of particles or fields about their equilibrium positions) propagates at the phase and group velocities parallel or antiparallel to the propagation direction, which is common to longitudinal and transverse waves. Below oscillatory displacement, velocity and acceleration refer to the kinematics in the oscillating directions of the wave - transverse or longitudinal (mathematical description is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 French an ''équation'' is defined as containing one or more variables, while in English, any well-formed formula consisting of two expressions related with an equals sign is an equation. ''Solving'' an equation containing variables consists of determining which values of the variables make the equality true. The variables for which the equation has to be solved are also called unknowns, and the values of the unknowns that satisfy the equality are called solutions of the equation. There are two kinds of equations: identities and conditional equations. An identity is true for all values of the variables. A conditional equation is only true for particular values of the variables. An equation is written as two expressions, connected by a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sound Pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in W· m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is the sound pressure, * v is the particle velocity. Acoustic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Photonics Equations
This article summarizes equations used in optics, including geometric optics, physical optics, radiometry, diffraction, and interferometry. Definitions Geometric optics (luminal rays) General fundamental quantities Physical optics (EM luminal waves) There are different forms of the Poynting vector, the most common are in terms of the E and B or E and H fields. Radiometry For spectral quantities two definitions are in use to refer to the same quantity, in terms of frequency or wavelength. Equations Luminal electromagnetic waves Geometric optics Subscripts 1 and 2 refer to initial and final optical media respectively. These ratios are sometimes also used, following simply from other definitions of refractive index, wave phase velocity, and the luminal speed equation: \frac = \frac = \frac = \sqrt \,\! where: *''ε'' = permittivity of medium, *''μ'' = permeability of medium, *''λ'' = wavelength of light in medium, *''v'' = speed of light in media. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 constant'' or ''Dirac constant''. The general form of wavefunction for a system of particles, each with position r''i'' and z-component of spin ''sz i''. Sums are over the discrete variable ''sz'', integrals over continuous positions r. For clarity and brevity, the coordinates are collected into tuples, the indices label the particles (which cannot be done physically, but is mathematically necessary). Following are general mathematical results, used in calculations. Equations Wave–particle duality and time evolution Non-relativistic time-independent Schrödinger equation Summarized below are the various forms the Hamiltonian takes, with the corresponding Schrödinger equations and forms of wavefunction solutions. Notice in the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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'' ↔ ''R'' → ''c'' in the centre of mass frame, where ''a'' and ''b'' are the initial species about to collide, ''c'' is the final species, and ''R'' is the resonant state. Fundamental forces These equations need to be refined such that the notation is defined as has been done for the previous sets of equations. See also *Defining equation (physical chemistry) *Defining equation (physics) * List of electromagnetism equations *List of equations in classical mechanics *List of equations in quantum mechanics *List of equations in wave theory * List of photonics equations *List of relativistic equations *Relativistic wave equations In physics, specifically relativistic quantum mechanics (RQM) and its applications to particle physics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Equations In Gravitation
This article summarizes equations in the theory of gravitation. Definitions Gravitational mass and inertia A common misconception occurs between centre of mass and centre of gravity. They are defined in similar ways but are not exactly the same quantity. Centre of mass is the mathematical description of placing all the mass in the region considered to one position, centre of gravity is a real physical quantity, the point of a body where the gravitational force acts. They are equal if and only if the external gravitational field is uniform. Newtonian gravitation Gravitoelectromagnetism In the weak-field and slow motion limit of general relativity, the phenomenon of gravitoelectromagnetism (in short "GEM") occurs, creating a parallel between gravitation and electromagnetism. The ''gravitational field'' is the analogue of the electric field, while the ''gravitomagnetic field'', which results from circulations of masses due to their angular momentum, is the analogue of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Equations In Fluid Mechanics
This article summarizes equations in the theory of fluid mechanics. Definitions Here \mathbf \,\! is a unit vector in the direction of the flow/current/flux. Equations See also *Defining equation (physical chemistry) *List of electromagnetism equations *List of equations in classical mechanics *List of equations in gravitation *List of equations in nuclear and particle physics *List of equations in quantum mechanics *List of photonics equations *List of relativistic equations *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 ... Sources * * * * * * * * * Further reading * * * * {{SI units navbox Physical quantities SI units Physical chemistry Equations of physics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Equations In Classical Mechanics
Classical mechanics is the branch of physics used to describe the motion of macroscopic objects. It is the most familiar of the theories of physics. The concepts it covers, such as mass, acceleration, and force, are commonly used and known. The subject is based upon a three-dimensional Euclidean space with fixed axes, called a frame of reference. The point of concurrency of the three axes is known as the origin of the particular space. Classical mechanics utilises many equations—as well as other mathematical concepts—which relate various physical quantities to one another. These include differential equations, manifolds, Lie groups, and ergodic theory. This article gives a summary of the most important of these. This article lists equations from Newtonian mechanics, see analytical mechanics for the more general formulation of classical mechanics (which includes Lagrangian and Hamiltonian mechanics). Classical mechanics Mass and inertia Derived kinematic quantit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defining Equation (physical Chemistry)
In physical chemistry, there are numerous quantities associated with chemical compounds and reactions; notably in terms of ''amounts'' of substance, ''activity'' or ''concentration'' of a substance, and the ''rate'' of reaction. This article uses SI units. Introduction Theoretical chemistry requires quantities from core physics, such as time, volume, temperature, and pressure. But the highly quantitative nature of physical chemistry, in a more specialized way than core physics, uses molar amounts of substance rather than simply counting numbers; this leads to the specialized definitions in this article. Core physics itself rarely uses the mole, except in areas overlapping thermodynamics and chemistry. Notes on nomenclature ''Entity'' refers to the type of particle/s in question, such as atoms, molecules, complexes, radicals, ions, electrons etc. Conventionally for concentrations and activities, square brackets are used around the chemical molecular formula. For an arbitr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rita G
Rita may refer to: People * Rita (given name) * Rita (Indian singer) (born 1984) * Rita (Israeli singer) (born 1962) * Rita (Japanese singer) * Eliza Humphreys (1850–1938), wrote under the pseudonym Rita Places * Djarrit, also known as Rita, a community in the Marshall Islands * 1180 Rita, an asteroid * Rita, West Virginia * Santa Rita, California (other), several places Film, television, and theater * ''Rita'' (1959 film), a 1959 Australian television play * ''Rita'' (2009 Italian film), a 2009 Italian film * ''Rita'' (2009 Indian film), a 2009 Marathi film directed by Renuka Shahane * ''Rita'' (TV series), a Danish television show * RITA Award, an award for romantic fiction * ''Educating Rita'', a 1980 stage play by Willy Russel ** ''Educating Rita'' (film), a 1983 British film based on that play *Rita Santos, an adult mermaid on the TV series ''Mako Mermaids'' Music * ''Rita'' (opera), an 1841 opera by Gaetano Donizetti Albums * ''Rita'' (Rita Yahan-Farouz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wave Equation
The (two-way) wave equation is a second-order linear partial differential equation for the description of waves or standing wave fields — as they occur in classical physics — such as mechanical waves (e.g. water waves, sound waves and seismic waves) or electromagnetic waves (including light waves). It arises in fields like acoustics, electromagnetism, and fluid dynamics. Single mechanical or electromagnetic waves propagating in a pre-defined direction can also be described with the first-order one-way wave equation which is much easier to solve and also valid for inhomogenious media. Introduction The (two-way) wave equation is a second-order partial differential equation describing waves, including traveling and standing waves; the latter can be considered as linear superpositions of waves traveling in opposite directions. This article mostly focuses on the scalar wave equation describing waves in scalars by scalar functions of a time variable (a variable repres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
