mach number

American  

Or Mach number

noun

1. a number indicating the ratio of the speed of an object to the speed of sound in the medium through which the object is moving. M

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Mach number British  

noun

1. Often shortened to: Mach.  (often not capital) the ratio of the speed of a body in a particular medium to the speed of sound in that medium. Mach number 1 corresponds to the speed of sound

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Mach number Scientific  

1. 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.

2. See also subsonic supersonic transonic

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Mach number Cultural  

1. The speed of an object, measured in multiples of the speed of sound. Thus, an airplane traveling at the speed of sound is said to be at Mach 1; at twice the speed of sound, it is said to be at Mach 2.

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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

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

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

As you accelerate to orbital speeds, you have to increase your Mach number.

From Forbes