Answer
a. 110 m/s
b. 270 m/s
Work Step by Step
a. At that temperature, the speed of sound is 345.4 m/s, using the formula on page 329. Represent the Mach number by M.
$$M=\frac{v_{obj}}{v_{sound}}$$
$$v_{obj}=Mv_{sound}=0.33(345.4m/s)=113.98 m/s \approx 110 m/s$$
b. $M=\frac{v_{obj}}{v_{sound}}$
$$v_{sound}=\frac{v_{obj}}{M}=\frac{3000000m/3600s}{3.1}\approx 270 m/s$$
