SUPERSONICSPEED
Supersonic speed
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C at sea level, this speed is approximately 343 m/s, 1,125 ft/s, 768 mph, 667 knots, or 1,235 km/h. Speeds greater than five times the speed of sound are often referred to as hypersonic. Flight during which only some parts of the air surround an object, such as the ends of rotor blades, reach supersonic speeds are called transonic. This occurs typically somewhere between Mach 0.8 and Mach 1.23The above text is a snippet from Wikipedia: Supersonic speed
and as such is available under the Creative Commons Attribution/Share-Alike License.