Mach number
1
7.7
- noun
- /mɑk ˈnʌmbər/
- Specialized
- The fighter jet was designed to perform optimally at high Mach numbers during supersonic flight.
- high Mach number
Examples
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At low to moderate Mach numbers, the turbojets provide thrust.
Academic text (2001) -
Pilots adjust their flight plans based on the current Mach number to ensure safety and efficiency.
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And by the way, no matter the medium or the speed of sound within it, reaching similar Mach numbers creates similar physical phenomena.
Academic text (2006) -
They don't deal with stuff the best they can deal with low Mach numbers for the most part.
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The star's guts spew forth at 12,000 miles a second, creating shock waves whose Mach numbers are in the thousands.
Academic text (2006) -
The exoskeletal engine derives its name from its non-standard design and is ideal for high Mach number applications.
Academic text (2001) -
This offers significant weight and volume reductions, while the performance, which varies significantly with Mach number, exceeds that of a rocket over most of the flight trajectory.
Academic text (2001) -
Aerodynamic pressure due to airflow is a follower-type load that usually appears in flight vehicles traveling at supersonic Mach numbers.
Academic text (2018) -
Note that the average SW velocity in the time interval 0 < t < 70 ps in water is 4 km/s and the average Mach number is 2.7.
Academic text (2018) -
CFD research using the HECToR supercomputer in Britain included a study of this transonic cavity flow at Mach number 0.85.
Academic text (2009)
Synonyms
15
6.9
A speed that shows how many times faster something is than the speed of sound
How Fast
- Specialized
1
7.5
15
6.7
- Specialized
1
7.7
- Specialized
1
9.6
- Specialized
3
6.4
Surface Forms
Morphology
The phrase is compositional: 'Mach' denotes multiples of the speed of sound and 'number' indicates a numerical measure, so a learner who knows both constituents can infer that 'Mach number' is the ratio of an object's speed to the speed of sound. Although technical, it follows a straightforward modifier+noun pattern and is widely borrowed across languages, making the meaning predictable to learners who know the parts.
Etymology
Mach number comes from the scientist Mach, who studied the 'speed of sound', and the word number shows it is a measure or comparison. So, it tells how many times faster something is than the 'speed of sound' — for example, 'Mach 2' means twice the 'speed of sound'.