1. During a polytropic process, 10 lb of an ideal gas, whose R=40 ft.lb/lb.R and c = 0.25 Btu/lb.R, changes state from 20 psia and 40°F to 120 psia and 340°F. Determine (a) n, (b) AU and AH, (c) AS, (d) Q, (e) SpdV, (f)- SVdp. (g) If the process is steady flow during which AK = 0, what is W?. What is AK if W, = 0? (h) What is the work for a nonflow process?

Calculate the energy requirement to raise the temperature of 1 kg of water from 60 ° C of water to 90 ° C using the following approach;   a. Average specific heat usage (Tab A Singh's Book. 4.1) = kJ b. The enthalpy change in the water - vapor saturation table (Tab A Singh's Book. 4.2) = kJ

3. Air is contained within a piston-cylinder assembly The cross sectional area of the piston is 0.01 m². Initially the piston is at 1 bar and 25°C, 10 cm above the base of the cylinder. In this state, the spring exerts no force on the piston. The system is then reversibly heated to 100°C. As the spring is compressed, it exerts a force on the piston according to: F=-kx where k= 50,000 N/m and x is the displacement length from its uncompressed position. Determine the work done. a. -166 J b. -216 J c. 166 J d. 216 J