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 (kernel) system would be implemented by starting with the existing BSD code, and re-implementing it bit by bit as inter-process communication-based (IPC-based) programs. Thus Mach would begin as a monolithic system similar to existing UNIX systems, and evolve more towards the microkernel concept over time. Mach started largely as an effort to produce a cleanly defined, UNIX-based, highly portable Accent. The result was a short list of generic concepts: Mach developed on Accent's IPC concepts, but made the system much more UNIX-like in nature, even able to run UNIX programs with little or no modification. To do this, Mach introduced the