A piston-cylinder assembly fitted with a paddle wheel contains air, initially at p1=30 lbf/in2, T1=540 °F, and V1=4 ft3. The air undergoes a process to a final state where p2=20 lbf/in2, V2=4.5 ft3. During the process, the paddle wheel transfers energy to the air by work in the amount 1 Btu, while the air transfers energy by work to by the piston in the amount 3.31 Btu. Assuming ideal gas behavior, determine for the air (a) the temperature at state 2, in °R.