Air is fed from a reservoir through a converging-diverging nozzle into a $1 / 2 \mathrm{in}$. ID drawn steel tube that is $15 \mathrm{ft}$ long. The flow in the tube is adiabatic, and the reservoir temperature and pressure are $70^{\circ} \mathrm{F}$ and 200 psia.

(a) What is the maximum flow rate (in $\mathrm{lb}_{\mathrm{m}} / \mathrm{s}$ ) that can be achieved in the tube?

(b) What is the maximum pressure at the tube exit at which this flow rate will be reached?

(c) What is the temperature at this point under these conditions?