Air undergoes a poly tropic process in a piston-cylinder assembly from P1 = 1 atm, T1 = 70ºF to P2 = 3 atm. Employing the ideal gas model with constant specific heats at 80ºF, determine the work and heat transfer per unit mass, in Btu/lbm, if
1. n = 1
2. n = the specific heat ratio, k