Final answer:
The maximum holding speed in a turbojet (including turbofan) above 14,000 feet is typically around Mach 0.83 to Mach 0.85. Mach number is the ratio of the speed of an object to the speed of sound in the surrounding medium.
Step-by-step explanation:
Above 14,000 feet, the maximum holding speed of a turbojet, including a turbofan, is usually between Mach 0.83 and Mach 0.85. The ratio of an object's speed to the sound speed in the surrounding medium is called its Mach number. The maximum holding speed drops as altitude increases due to the slowing of sound.
For instance, at 14,000 feet in altitude, the speed of sound would be approximately 295 meters per second if it were 340 meters per second at sea level. Consequently, at elevations above 14,000 feet, a turbojet's maximum holding speed would be approximately 295 x 0.83 = 244 meters per second.