- Rayl
A rayl is one of two units of
acoustic impedance . When sound waves pass through any physical substance the pressure of the waves causes the particles of the substance to move. The sound impedance is the ratio between thesound pressure and theparticle velocity it produces. The impedance is one rayl if unit pressure produces unit velocity.The units are named for
Robert John Strutt, 4th Baron Rayleigh (1875–1947). They have the same name when using either the CGS definition or the MKS-based definition, but not the same value:* In MKS units, 1 rayl equals 1 pascal-
second permeter (Pa·s·m−1), or equivalently 1newton -second per cubic meter (N·s·m−3). InSI base unit s, that’s kg∙s−1∙m−2.
* In CGS units, 1 rayl equals 1dyne -second per cubic centimeter (dyn·s·cm−3).1 CGS rayl = 10 MKS rayls.
External links
* [http://www.unc.edu/~rowlett/units/dictR.html Dictionary of Physics Units of Measurement]
* [http://www.sizes.com/units/rayl.htm A discussion of the history and ambiguity of the rayl]
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