mach number
Americannoun
noun
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The ratio of the speed of a body to the speed of sound in a particular medium, usually the Earth's atmosphere. For example, an aircraft flying through air at twice the speed of sound has a Mach number of 2. The Mach number of an aircraft travelling at a given velocity depends on the altitude of the aircraft and other atmospheric conditions that affect the speed of sound near the aircraft.
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See also subsonic supersonic transonic
Discover More
The unit is named after Ernst Mach, an Austrian physicist of the nineteenth century.
Etymology
Origin of mach number
First recorded in 1935–40; after Ernst Mach
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
That same year, she co-authored the report "Effects of Nose Angle and Mach Number on Transition on Cones at Supersonic Speeds," the first of around a dozen research reports she would produce for the space agency.
From Fox News
She then became an aerospace engineer specializing in aerodynamics in 1958, co-authoring her first report that same year: “Effects of Nose Angle and Mach Number on Transition on Cones at Supersonic Speeds.”
From The Verge
The results of the work would come to fruition in 1958, in Mary’s first report, coauthored with Czarnecki: “Effects on Nose Angle and Mach Number on Transition on Cones at Supersonic Speeds,” published in September 1958.
From Literature
Fujino discovered the optimum Over-The-Wing Engine Mount configuration, which reduces wave drag at a high Mach number, and applied it to the HondaJet, a clean sheet design.
From Forbes
His final Mach number was 1.25.
From BBC
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
