what is the speed of the sound in air
Speed of sound 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 0 °C (32 °F), the speed of sound is 331.2 metres per second (1,087 ft/s; 1,192 km/h; 741 mph; 644 kn). At 20 °C (68 °F), the speed of sound is 343 metres per second (1,125 ft/s; 1,235 km/h; 767 mph; 667 kn), or a kilometre in 2.91 s or a mile in 4.69 s.
Cruise (aeronautics) The typical cruising airspeed for a long-distance commercial passenger aircraft is approximately 475–500 knots (878–926 km/h; 546–575 mph).