a) Consider a machine that uses compressed air to perform work. After the working cylinder (volume 12 l) is pre-charged to a pressure of 20 bar at the ambient temperature of 25 oC, piston is released. What is the maximal amount of work that can be done by this machine and under what conditions? Machine uses ideal diatomic gas (CV=5/2 R ) and is operated under ambient pressure of 1 bar.
b) How much work can be done by the machine if there is no resistance to the piston besides atmospheric pressure? Assume that motion of the piston happens faster than heat can travel through walls of the cylinder.
c) How much heat will be transferred and how will internal energy of the gas in the cylinder change as it comes to thermal equilibrium with the atmosphere after the process in b? Piston movement is not restricted.