Speed of Sound in Air

The speed of sound in a gas depends primarily on the temperature, and can be estimated using the following formula from the kinetic theory of gases: ^E.12

$$c = \sqrt{\gamma R T},$$

where adiabatic gas constant is $\gamma=1.4$ for air at standard temperature and pressure (STP) (standard temperature is zero degrees centigrade), $R=286$ is the ideal gas constant for air (in meters-squared per second-squared per degrees-Kelvin-squared), and $T$ is absolute temperature in degrees Kelvin (which equals degrees centigrade + 273.15). For example, at zero degrees centigrade (32 degrees Farenheit), the speed of sound is calculated to be 1085.1 feet per second. At 20 degrees centigrade, we get 1124.1 feet per second.