Question

What is Mach number?

(a) Speed of object * speed of sound

(b) Speed of object /speed of sound

(c) Speed of object + speed of sound

(d) Speed of object- speed of sound

The question was asked in an international level competition.

I'd like to ask this question from Area Velocity Relationship for Compressible Flow topic in division Compressible Flow of Fluid Mechanics

Answer 1

Right option is (b) Speed of object /speed of sound

To explain I would say: Mach number is defined as the ratio of the speed of an object to the speed of sound. Mach number is denoted by ‘M’. Mach number ranges from zero to infinity. It falls into several flow regimes.