Problem 2 Consider a closed gas power cycle where air at 116 kPa, 28°C is first compressed by an isentropic compressor with a pressure ratio of 9. Then, 700 kJ/kg of heat is added using an isochoric heat exchanger. Next, the air is expanded through a turbine which has an isentropic efficiency of 77%. Finally, heat is rejected isobarically in a heat exchanger. Pressure drop in the pipes are negligible. Assuming variable specific heats: (a) Calculate the net work generated by this cycle in kJ/kg. (b) Determine the thermal efficiency. (c) Determine the maximum theoretical thermal efficiency that can be achieved by this cycle. (d) If 10 MW is desired to be generated by this cycle, determine the required mass flow rate. (e) Show the cycle on T-s and P-v diagrams. 3-34 50 kN- .m if the For each section illustrated, find the second moment of area, the location of the neutral axis. and the distances from the neutral axis to the top and bottom surfaces. Consider that the section is transmitting a positive bending moment about the z axis, M., where M dimensions of the section are given in ips units, or M 1.13 kN m if the dimensions are in SI units. Determine the resulting stresses at the top and bottom surfaces and at every abrupt change in the cross section. Problem 3-34 40 mm 6 mm (a) D D 24 mm 25 mm 6 mm C 25 mm B 25 mm 6 mm D 75 100 12.5 12.5- B 12.5 A T 25 50 100 (c) Dimensions in mm B 10 mm A 40 mm- 6 mm (b) OA-C 150 mm- 30 mm 40 mm->>> (d) B 75 mm