The Speed of Sound

From Wikipedia:

The speed of sound is the distance travelled per unit time by a sound wave as it propagates through an elastic medium. At 20 °C (68 °F), the speed of sound in air is about 343 metres per second (1,235 km/h; 1,125 ft/s; 767 mph; 667 kn), or a kilometre in 2.9 s or a mile in 4.7 s. It depends strongly on temperature, but also varies by several metres per second, depending on which gases exist in the medium through which a soundwave is propagating.

The speed of sound in an ideal gas depends only on its temperature and composition. The speed has a weak dependence on frequency and pressure in ordinary air, deviating slightly from ideal behavior.

In common everyday speech, speed of sound refers to the speed of sound waves in air. However, the speed of sound varies from substance to substance: sound travels most slowly in gases; it travels faster in liquids; and faster still in solids. For example, (as noted above), sound travels at 343 m/s in air; it travels at 1,481 m/s in water (almost 4.3 times as fast as in air); and at 5,120 m/s in iron (almost 15 times as fast as in air). In an exceptionally stiff material such as diamond, sound travels at 12,000 metres per second (39,000 ft/s)^[1]—about 35 times as fast as in air—which is around the maximum speed that sound will travel under normal conditions.

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