Critical Mach number Critical Mach number In aerodynamics, the critical Mach number (Mcr or M* ) of an aircraft is the lowest Mach number at which the airflow over some point of the aircraft reaches the speed of sound, but does not exceed it. At the lower critical Mach number, airflow around the entire aircraft is subsonic. At the upper critical Mach number, airflow around the entire aircraft is supersonic. For an aircraft in flight, the speed of the airflow around the aircraft differs considerably in places from the airspeed of the aircraft; this is due to the airflow having to speed up
Mach Five car appeared to have the same functions as the Mach Five in the original series, but the buttons Speed pressed to activate them seemed more or less random, with the same button activating different abilities (or different buttons activating the same ability) in different episodes. In 2000, a prototype Mach Five with actual cutting blades was produced as a concept car. 100 production models were planned to be made in 2002 as a street legal vehicle. Built on a 2001 Chevrolet Corvette Chassis, the body was to be extensively modified to look like the Mach Five. It was to have