Here's why:
* Mach number: A Mach number represents the ratio of an object's speed to the speed of sound in the surrounding medium.
* Speed of sound: The speed of sound varies depending on factors like temperature and altitude, but it's approximately 767 mph (1,230 km/h) at sea level and standard temperature.
* Mach 2: An object traveling at Mach 2 is moving at twice the speed of sound, or about 1,534 mph (2,460 km/h).
Examples of things that travel at Mach 2:
* Some military fighter jets, like the F-16 and Eurofighter Typhoon
* Some high-speed missiles
Note: "Twice the speed of sound" is a relative term because the speed of sound isn't constant. A plane traveling at Mach 2 at high altitude would be going faster than a plane traveling at Mach 2 at sea level.
