speed of sound

The speed of sound, or of acoustic traveling waves, is a physical constant for any given medium at a specific pressure and temperature. In dry air at sea level at 0 degrees Celsius , the speed of sound is approximately 331.4 meter s per second (m/s). Temperature, pressure, and humidity affect this value to some extent.

In most liquids and solids, the speed of sound is greater than in air at sea level. In part, this is because traveling waves in air occur because of compression, but traveling waves in solids and liquids occur because of lateral motion of the molecules, a phenomenon that generally propagates faster. The higher speed of sound in liquids and solids, compared with gases, is also partly the result of the fact that liquids and solids are usually more dense than gases. Traveling-wave speed generally increases with increasing density and hardness of the medium.

Also see Table of Physical Units and Constants.