In Example 3.18, what is the length of the duct required to choke the flow?

Data From Example 3.18:

Consider the flow of air through a pipe of inside diameter \(=0.4 \mathrm{ft}\) and length \(=5 \mathrm{ft}\). The inlet flow conditions are \(M_{1}=3, p_{1}=1 \mathrm{~atm}\), and \(T_{1}=300 \mathrm{~K}\). Assuming \(f=\mathrm{const}=0.005\), calculate the flow conditions at the exit, \(M_{2}, p_{2}, T_{2}\), and \(p_{o_{2}}\).