Mach

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A Unix-like operating system developed at Carnegie-Mellon University in the period between 1985 and 1994. It was designed with a microkernel architecture that makes it easily portable to different platforms. Operating systems based on Mach include NextStep, OSF/1 and Mac OS X. See microkernel, Mac OS X and Open Group.

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Refers to a Mach number, or the ratio of the speed of an airplane to the speed of sound in the same atmospheric conditions. It is also used as a speed unit. The speed of sound, or Mach 1, is equal to 340.5 m/s, 661 knots, 761 miles per hour, or 1225.5 km/h at sea level under standard conditions, and it decreases with altitude. Above the tropopause (about 36,090 ft, or 11 km), Mach 1 is 295.5 m/s, 574 knots, 658 miles per hour, or 1063.2 km/h. Named after Ernst Mach (1838–1916).



Speed of sound as a function of altitude.

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For a list of words related to Mach, see:

• Space Exploration and Rocketry - Mach: number expressing ratio of speed of a body with respect to surrounding air or fluid; Mach 1 is speed of sound, supersonic being above Mach 1, subsonic below

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Dansk (Danish)
abbr. - mach (f.eks. mach-tal, mach-område)
n. - maskine, maskineri, maskinist

Français (French)
abbr. - (abrév) de machine, machinerie, machiniste
n. - (Phys) (nombre) de Mach

Deutsch (German)
abbr. - Maschine, Mechanismus, Maschinenbauer
n. - (Phys.) Machsche Zahl

Ελληνική (Greek)
abbr. - μαχ (μονάδα ταχύτητας)
n. - μαχ (μονάδα ταχύτητας)

Italiano (Italian)
(numero di) Mach (fis.)

Português (Portuguese)
abbr. - maquinaria (f)
n. - medida de velocidade, sistema operacional do computador NeXT (Comp.)

Русский (Russian)
машина, машинист

Español (Spanish)
abbr. - forma abreviada de número de Mach, máquina, maquinaria, maquinista
n. - número de Mach

Svenska (Swedish)
abbr. - machine
n. - mach

中文（简体）(Chinese (Simplified))
机器, 计算机

中文（繁體）(Chinese (Traditional))
abbr. - 機器, 電腦
n. - 機器, 電腦

한국어 (Korean)
abbr. - mach number(마하 수), machinery(기계류), machinist(기계 운전자)
n. - 마하(초음속의 단위)

日本語 (Japanese)
n. - マッハ

עברית (Hebrew)
abbr. - ‮מכונה, מכונות וחלקיהן, מכונאי, בונה מכונות‬
n. - ‮מאך (מהירות הקול)‬

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