The term supersonic is use to define a speed that is over the speed of sound (Mach 1). At a typical temperature like 70 degrees Fahrenheit (21.1 °C), the threshold value required for an object to be traveling at a supersonic speed is approximately 344 m/s, 1,129 ft/s, 770 mph or 1,238 km/h. Speeds greater than 5 times the speed of sound are often referred to as hypersonic. Speeds where only some parts of the air around an object (such as the ends of rotor blades) reach supersonic speeds are labeled transonic (typically somewhere between Mach 0.8 and Mach 1.2).