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 1 Racing standings, he left the team for Jackson Bros. Motorsports, taking Skoal and No. 33 with him. In 1989, Mach 1 switched to the No. 66 and signed rookie driver Rick Mast. In their first race together, the Daytona 500, Mast drove the unsponsored car to a sixth-place finish, an accomplishment he later said was the one he was the most proud of. Mast and Mach 1 ran twelve more races together that season, they were unable to duplicate that effort. Needham closed the team and sold it to their crew chief, Travis Carter. Travis Carter Motorsports entered NASCAR competition in