* Mach Number: Mach number represents the ratio of an object's speed to the speed of sound.

* Speed of Sound: The speed of sound varies with temperature, but at standard sea level conditions (15°C or 59°F), it's approximately 767 mph.

Calculation:

* Mach 0.6 = 0.6 * 767 mph

* Mach 0.6 ≈ 460 mph

Therefore, Mach 0.6 is approximately 460 mph.