Speed of sound

The speed of sound is the distance traveled per unit time by a sound wave propagating through an elastic medium. In dry air at 20 °C, the speed of sound is 343.2 metres per second (1,126 ft/s). This is 1,236 kilometres per hour (768 mph; 667 kn), or a kilometre in 2.914 s or a mile in 4.689 s.

The speed of sound in an ideal gas is independent of frequency, but does vary slightly with frequency in a real gas. It is proportional to the square root of the absolute temperature, but is independent of pressure or density for a given ideal gas. The speed of sound in air varies slightly with pressure only because air is not quite an ideal gas. Although, in the case of gas only the speed of sound is expressed in terms of a ratio of both density and pressure, these quantities cancel in ideal gases at any given temperature, composition, and heat capacity. This leads to a velocity formula for ideal gases which includes only the latter independent variables.

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 faster in liquids and non-porous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), as in air at 20 °C. Sound waves in solids are composed of compression waves (just as in gases and liquids), but there is also a different type of sound wave called a shear wave, which occurs only in solids. These different types of waves in solids usually travel at different speeds, as exhibited in seismology. The speed of a compression sound wave in solids is determined by the medium's compressibility, shear modulus and density. The speed of shear waves is determined only by the solid material's shear modulus and density.

Speed of sound (disambiguation)

The speed of sound is a physical characteristic.

Speed of sound may also refer to:

See also

Speed of Sound (roller coaster)

Speed of Sound is a Boomerang roller coaster in Walibi Holland. It was manufactured by Vekoma and opened in 2000 as La Via Volta. It was open until 2007 when the park announced it would be shut down. That year, the train was sold to Pleasurewood Hills in England and now operates on Wipeout and the track remained in place at Walibi World. On 30 January, Walibi Holland announced that the La Via Volta will reopen in 2011, with a new style train from Vekoma under the name of Speed of Sound. P&P Projects was responsible for the design and build of this new attraction. Walibi Holland announced that it held a competition to win tickets for the opening of the roller coaster on April 6, 2011

References

External links

Media related to Roller coasters at Walibi Holland at Wikimedia Commons