Air is contained in a piston - cylinder device at 600 kPa and oC, and occupies a volume of 0.8 m3. The air undergoes and isothermal (constant temperature) process until the pressure in reduced to 300 kPa. The piston is now fixed in place and not allowed to move while a heat transfer process takes place until the air reaches 27oC.
(a) Sketch the system showing the energies crossing the boundary and the P-V diagram for the combined processes.
(b) For the combined processes determine the net amount of heat transfer, in kJ, and its direction. Assume air has constant specific heats evaluated at 300 K.