5.29 A refrigeration cycle operating between two reservoirs receives energy QC from a cold reservoir at TC = 275 K and rejects energy QH to a hot reservoir at TH = 315 K. For each of the following cases, determine whether the cycle operates reversibly, operates irreversibly, or is impossible: (a) QC = 1000 kJ, Wcycle = 80 kJ. (b) QC = 1200 kJ, QH = 2000 kJ. (c) QH = 1575 kJ, Wcycle = 200 kJ. (d) COPR = 6

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