Mach number temperature generally decreases with increasing altitude between sea level and , the speed of sound also decreases. For example, the standard atmosphere model lapses temperature to at altitude, with a corresponding speed of sound (Mach1) of , 86.7% of the sea level value. While the terms "subsonic" and "supersonic", in the purest sense, refer to speeds below and above the local speed of sound respectively, aerodynamicists often use the same terms to talk about particular ranges of Mach values. This occurs because of the presence of a "transonic regime" around M = 1 where approximations of the Navier-Stokes equations used
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