The speed with which a sound wave travels through a gas is given by
where is the heat capacity ratio, P is the ambient pressure, and is the density.
From the ideal gas law,
where m is the molar mass, R is the universal gas constant, and T is the temperature (which must be given in Kelvin), so
so the speed of sound can also be written
Air, Mach Number, Speed of Light, Sound, Sound Wave
