What is the speed of sound in air, water .. ?
The speed of sound in air at a temperature of 0 ºC and 50% relative humidity is 331.6 m/s. The speed is proportional to the square root of absolute temperature and it is therefore about 12 m/s greater at 20 ºC. The speed is nearly independent of frequency and atmospheric pressure but the resultant sound velocity may be substantially altered by wind velocity. A good approximation for the speed of sound in other gases at standard temperature and pressure can be obtained from c = sqrt (gamma x P / rho) where gamma is the ratio of specific heats, P is 1.013E5 Pa and rho is the density. The speed of sound in water is approximately 1500 m/s. It is possible to measure changes in ocean temperature by observing the resultant change in speed of sound over long distances. The speed of sound in an ocean is approximately: c = 1449.2 + 4.6T – 0.055T^2 + 0.00029T^3 + (1.34-0.01T)(S-35) + 0.016z T temp in degrees Celsius, S salinity in parts per thousand z is depth in meters See also CRC Handbook of C
