Instructions: ALWAYS indicate the basic equation at the start of each solution. Write your solutions clearly and orderly. 1) (10%) A certain quantity of air is initially at 200 kPa (absolute) and 35C. If the final state after a thermodynamic process is 120 kPa and 10C, find the polytropic index of the process and describe what type of process this index represents. 2) (15%) An unknown gas at p=95 psia and V=4 ft undergoes a process that results in p=15 psia and V2=16.56 ft, during which the enthalpy decreases to 83 Btu and c =0.1573 Btu/lbm-R. Determine a) AU, b) Cp, and c) R. 3) (15%) A 3-m rigid tank contains helium at 800 kPa and 30C. A balloon is filled with the helium until the pressure in the tank falls to 200 kPa (constant T). What is the mass of helium removed from the tank?