Sound Waves

Sound is a longitudinal compression-expansion wave through matter. The wave speed is

${\displaystyle c=(\gamma RT_{abs})^{1/2}}$ (2.11)

where ${\displaystyle \gamma }$ and ${\displaystyle R}$ are constants and ${\displaystyle T_{abs}}$ is the absolute temperature. The absolute temperature is measured in Kelvins and is numerically given by

${\displaystyle T_{abs}=T_{C}+273.16^{\circ }}$ (2.12)

where ${\displaystyle T_{C}}$ is the temperature in Celsius degrees. The angular frequency of sound waves is thus given by

${\displaystyle \omega =ck=(\gamma RT_{abs})^{1/2}k.}$ (2.13)

The speed of sound in air at normal temperatures is about ${\displaystyle 340{\mbox{ m}}{\mbox{ s}}^{-1}}$.