Mach number Mach number In fluid dynamics, the Mach number (M or Ma) (; ) is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound. where: By definition, at Mach1, the local flow velocity is equal to the speed of sound. At Mach0.65, is 65% of the speed of sound (subsonic), and, at Mach1.35, is 35% faster than the speed of sound (supersonic). The local speed of sound, and thereby the Mach number, depends on the condition of the surrounding medium, in particular the temperature. The Mach number is primarily used to determine
Mach a Šebestová students and incorrigible urchins Horáček and Pažout, are the main antagonists of the series. Mach a Šebestová Mach a Šebestová (in English: Mach and Šebestová or Max and Sally) is a Czech cartoon series. It was created by writer Miloš Macourek, director Jaroslav Doubrava, and animator Adolf Born. The animated characters were voiced by Petr Nárožný. The story follows the adventures of two third-year pupils and a torn off telephone receiver. The first series of 13 episodes was broadcast on Czechoslovak Television in 1982. Mach a Šebestová is one of the most popular series made for children's television programme Večerníček.