Q2. (20 points). the lower yield point for an iron that has an average grain diameter of 5 × 10-2 mm is 135 mpa (19,500 psi). at a grain diameter of 8 × 10- 3 mm, the yield point increases to 260 mpa (37,500 psi). at what grain diameter will the lower yield point be 205 mpa (30,000 psi)?

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?