The supersonic speed of an aeroplane is expressed in:
2023
The supersonic speed of an aeroplane is expressed in:
- A.
Mach number
- B.
Decibel
- C.
Hertz
- D.
None of them
Attempted by 26 students.
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Correct answer: A
The supersonic speed of an aeroplane is expressed using the Mach number.
The Mach number (M) is the ratio of the speed of an object to the speed of sound in the surrounding medium: M = (speed of the object) / (speed of sound).
Based on the Mach number, flight is classified as subsonic (M < 1), transonic (M ~ 1), supersonic (M > 1, roughly Mach 1 to Mach 5), and hypersonic (M > 5). An aeroplane is therefore 'supersonic' when its Mach number is greater than 1, i.e. it travels faster than the speed of sound.
Hence, the correct answer is the Mach number.