A simply supported beam spans 20 ft and carries a uniformly distributed dead load of 0.8 kip/ft, including the beam self-weight, and a live load of 2.3 kip/ft. Determine the minimum required plastic section modulus (Zx) and select the lightest-weight W-shape to carry the moment. Consider only the limit state of yielding and use A992 steel.

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?