Air enters an approximately frictionless duct with $V_{1}=70 \mathrm{m} / \mathrm{s}, T_{1}=600 \mathrm{K},$ and $P_{1}=350$ kPa. Letting the exit temperature $T_{2}$ vary from 600 to 5000
$\mathrm{K},$ evaluate the entropy change at intervals of $200 \mathrm{K},$ and plot the Rayleigh line on a $T$ -s diagram.