Mach number

Mach number is a way to measure how fast something is moving compared to the speed of sound in the surrounding air or fluid. When an object travels at Mach 1, it's moving at the speed of sound, while Mach 2 means it's twice as fast as sound, and so on. This measurement is particularly useful for aircraft and rockets, where understanding how speed affects aerodynamic forces and the formation of shock waves becomes critically important.