Mach number which was also unit-first, and may have influenced the use of the term Mach. In the decade preceding faster-than-sound human flight, aeronautical engineers referred to the speed of sound as "Mach's number", never "Mach 1". Mach number is useful because the fluid behaves in a similar manner at a given Mach number, regardless of other variables. As modeled in the International Standard Atmosphere, dry air at mean sea level, standard temperature of , the speed of sound is . The speed of sound is not a constant; in a gas, it increases as the absolute temperature increases, and since atmospheric
Kawasaki H2 Mach IV Kawasaki H2 Mach IV The Kawasaki H2 Mach IV was a 750 cc 3-cylinder two-stroke production motorcycle manufactured by Kawasaki. The H2 was a Kawasaki triple sold from September 1971 through 1975. A standard, factory produced H2 was able to travel a quarter mile from a standing start in 12.0 seconds. It handled better than the Mach III that preceded it. By the standards of its time, its handling was sufficient to make it the production bike to beat on the race track. Nonetheless, its tendency to pull wheelies and a less than solid feel through high speed corners led