2008 Semifinal Exam 6 The negative net work reflects that the gas does work on the outside world.The efficiency of the process is then 2958 e= 932=5 It isn't much more work to fill in all of the values for both tables,a task that each student ought be able to do.One key point will be process 3-1,where W=-PAV.thethe rest are filled in by applications of Q+W=△U. Process W△U Point P V T 1→2 号31031 1 111 2→3 32132 0-36-36 2 3 188 3→1-号77-27 net 29-290 Solutions Copyright C2008 American Association of Physics TeachersSolutions 2008 Semifinal Exam 6 The negative net work reflects that the gas does work on the outside world. The efficiency of the process is then e = 29 93 / 2 = 58 93 It isn’t much more work to fill in all of the values for both tables, a task that each student ought be able to do. One key point will be process 3 → 1, where W = − P ∆ V . the the rest are filled in by applications of Q + W = ∆ U . Point P V T 1 1 1 1 2 32 1 32 3 1 8 8 Process Q W ∆ U 1 → 2 32 31 0 32 31 2 → 3 0 -36 -36 3 → 1 − 52 7 7 − 32 7 net 29 −29 0 Copyright c 2008 American Association of Physics Teachers