The Physics
Factbook
An encyclopedia of scientific essays

# Speed of Sound in Air

Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Zitzawitz, Neff & Mark Davids. Physics: Principles and Problems, New York: Glencoe, 1995: 308. "Sound waves move through air at sea level at a velocity of 343 m/s at room temperature (20 °C)." 343 m/s
(20 °C)
Trinklein, Frederick E. Modern Physics. New York. 1990: 256. "The speed of sound in air is 331.5 m/s at 0 °C." 331.5 m/s
(0 °C)
The World Book Encyclopedia. Vol 18. Chicago: World Book, 1995 . "Sound travels 1,268 feet (386 meters) per second through air at 212 °F (100 °C)." 386 m/s
(100 °C)
Speed of Sound. Hyperphysics. Carl R. Nave. Georgia State University. "Air, Temperature 0 °C, 331.5 m/s" 331.5 m/s
(0 °C)
"Air, Temperature 20 °C, 344 m/s" 344 m/s
(20 °C)

Sound surrounds us everyday. It also has great importance in our daily life. Sound is a longitudinal wave, which is produced by the compression and rarefaction of matter. The speed of sound is dependent on the medium through which the waves of sound travel. Sound travels slower in air in comparison with its travel in liquids and solids. The speed of sound in an object depends also on elasticity of the object. In fact, sound travels four times faster in liquids than in solids and around fifteen times faster in steel than in air. The properties that have an affect on the speed of sound in air are pressure, density, and molecular mass of the medium.

The lower the density that of a medium, the faster the speed of sound and the higher the compressibility is, the slower the sound travels. The speed of sound in air is approximately 331.5 m/s at 0 °C or around 1200 km per hour. The speed of sound through air is approximately 343 m/s at normal room temperature, which is at 20 °C. The speed of sound through air is 346 m/s at 25 °C. The speed of sound in air is approximately figured out by the formula …

speed of sound (m/s) = 331.5 + 0.60 T(°C)

For example, the speed of sound in air is 386 m/s at 100 °C. The sound of speed in air is increased by 0.60 m/s for each increase of degree in air temperature. The speed of sound is faster at higher temperatures because molecules collide more often.

Cheuk Wong -- 2000