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
Mach Rider against a hazard on the track, they obtain more points— this also replenishes Mach Rider's bullets. "Mach Rider" takes place in the year 2112, and planet Earth has been invaded by evil forces driving vehicles known as Quadrunners. The player controls Mach Rider, who travels from sector to sector on a high-powered superbike, searching for survivors and destroying any enemies in their path. In 1972, "Mach Rider" was originally released as a plastic race car or hot rod toy also by Nintendo that came with a ramp for jumping and a stick shift-like object with three different kinds of meters