Reconsider the process in Problem 3.170, in which three states were specified. Solve the problem by fitting a single smooth curve (P versus v) through the three points. Map out the path followed (including temperature and quality) during the process.

Data from problem 3.170

A cylinder containing 1 kg of ammonia has an externally loaded piston. Initially the ammonia is at 2 MPa and 180◦C. It is now cooled to saturated vapor at 40◦C and then further cooled to 20◦C, at which point the quality is 50%. Find the total work and the heat transfer for the process, assuming a piecewise linear variation of P versus V.