From WebRef.org

The phase speed of a sound wave in a compressible fluid if the expansions and compression are assumed to be adiabatic. This speed a is given by the formula

*a ^{2} = (c_{p}/c_{v}) RT*

where cp and cv are the specific heats at constant pressure and volume, respectively; R is gas constant; and T is the Kelvin temperature. The value of this speed under standard conditions in dry air is 331 meters per second. Compare Newtonian speed of sound.

Sponsor: CHEMICAL GUYS BUF503 - TORQ TORQX RANDOM ORBITAL POLISHER