Acylinder, closed by a piston, has a volume of 0.03m and contains air at 1 bar and 15°c. the air is compressed isentropically to one quarter of its original volume. it is then cooled in a reversible constant pressure process until the temperature falls to its initial value. finally, the air is expanded isentropically back to 1 bar. find the final temperature and the net work done during the sequence of processes.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers