How would i do Part B$,$ i believe i can solve Part A$,$ but i need B$.$

Problem $2$

Part.A:

Determine the ratio $=\frac{v}{c}$ and the $$ factor for each of the following cases.

a$)$ A car traveling at $60$ miles per hour.

b$)$ An airplane traveling at $1000$ km h

c$)$ A supersonic airplane traveling at Mach $2\mathrm{.}3.$

d$)$ The space shuttle traveling at $30,000k\frac{m}{h}.$

Mach number $($:$=\frac{v}{v_{\text{s}\text{o}\text{u}\text{n}\text{d}}}$