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 1 Racing Mach 1 Racing Mach 1 Racing was a NASCAR Winston Cup Series team. It was owned by Hollywood stuntman Hal Needham and actor Burt Reynolds. The team made its debut in 1981, fielding the No. 22 Skoal Pontiac driven by Stan Barrett. Barrett ran ten races for the team that season, his best finish coming at Talladega Superspeedway, where he finished 9th. Midseason, Mach 1 created a second car, the No. 33, driven by Harry Gant. Gant did not win that season, but he won three poles and had thirteen top-tens, finishing third in points. In 1982, Gant drove the