Thermodynamics

Q3: A piston cylinder device is filled with air (ideal gas) and the following sub-processes take place, in order: 1. Isothermal Compression from initial pressure of 10psia, and initial total volume of 4ft3 to a final pressure of P2=50 psia 2. Constant volume until the pressure decreased by 40 psia 3. Constant pressure, returning to its initial a) Sketch the PV diagram for the processes in series. b) Estimate the work for each process (Btu)