Respuesta :
The Mach number of a speed is given by how many times the speed is greater than the sound speed.
Therefore, to find each Mach number, let's divide the speed by the speed of sound:
A.
[tex]\frac{664}{332}=2[/tex]So here we have Mach 2. Since the speed is greater than the speed of sound, we have a supersonic sound.
B.
[tex]\frac{306}{332}=0.92[/tex]Here we have Mach 0.92. Since the speed is smaller than the speed of sound, we have a subsonic sound.
C.
Here we have to convert the given speed to m/s:
[tex]\begin{gathered} 140\text{ km/h}=\frac{140}{3.6}\text{ m/s}=38.89\text{ m/s} \\ \frac{38.89}{332}=\text{0}.12 \end{gathered}[/tex]Mach 0.12, subsonic.
D.
[tex]\begin{gathered} 7171\text{ km/h}=\frac{7171}{3.6}\text{ m/s}=1991.94\text{ m/s} \\ \frac{1991.94}{332}=6 \end{gathered}[/tex]Mach 6, supersonic.
