Question

Calculate the Mach number for sound given the temperature and the speeda. 332 m/s at 30°Cb. 340 m/s at -10°Cc. 6000 km/h at 13°Cd. 6000 km/h at -13°0

Answer 1

The Mach number indicates how many times a speed is greater than the speed of sound.

So, to find the Mach number, we just need to divide the speed by the speed of sound.

a) at 30°C, the speed of sound is 349 m/s, so we have:

`(332)/(349)=0.95`

b) at -10°C, the speed of sound is 325 m/s, so we have:

`(340)/(325)=1.05`

c) at 13°C, the speed of sound is 339 m/s. First, let's convert the speed from km/h to m/s:

`\begin{gathered} 6000\text{ km/h}=(6000)/(3.6)\text{ m/s}=1666.67\text{ m/s} \\ (1666.67)/(339)=4.92 \end{gathered}`

d) at -13°C, the speed of sound is 323 m/s, so we have:

`(1666.67)/(323)=5.16`