Three lbm of air at 300 F and 100 psia expands to twice its original volume in an adiabatic process carried out in a piston-cylinder apparatus. During the expansion the specific internal energy (u) decreases by 31.5 Btu/lbm. Recall for this type of process PV^k = constant, where k = 1.40.
a) Sketch the expansion process on the p-V diagram .
b) Determine the final pressure (psia) P2.
c) If p1V1/T1=p2v2/T2, determine the final temperature, T2.
d) Using the First Law, determine the work (Btu) that occurs, being careful about the mathematical sign.