The speed of sound is the distance travelled per unit time by a sound wave as it propagates through an elastic medium. In dry air at 20 Â°C (68 Â°F), the speed of sound is 343.2 metres per second (1,126 ft/s; 1,236 km/h; 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 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.
A flute is a musical instrument that produces sound when a stream of air is directed against the edge of a hole, causing the air within the body of the instrument to vibrate. Most flutes are tubular, but some are globular or other shapes.
A musician who plays the flute can be referred to as a flute player, flautist, flutist or, less commonly, fluter or flutenist. Flutes are the earliest extant musical instruments. A number of flutes dating to about 43,000 to 35,000 years ago have been found in the Swabian Jura region of present-day Germany. These flutes demonstrate that a developed musical tradition existed from the earliest period of modern human presence in Europe. Flutes, including the famous Bansuri, have been an integral part of Indian classical music since 1500 BC. A major deity of Hinduism, Krishna, has been associated with the flute.