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: The First Colony a 32-page book, and a 16-page book. Mach: The First Colony Mach: The First Colony is a role-playing game published by Alliance Publications in 1983. "Mach: The First Colony" is a science-fiction system in which the players are mercenaries on a frontier planet. The planet, its societies, and mixed technologies are described in detail. The first book (32 pages) covers character creation and combat; the second (32 pages) covers skills and creatures. The game includes an introductory scenario (16 pages). "Mach: The First Colony" was designed by Michael Lange with Martin Miller, and published by Alliance Publications in 1983 as