Giancoli Ch. 15 – p. 436, Problems #51-53, 55, 60, 61, 65 key

51) yes, his claim is impossible
52a) 220,000 J done by the gas
52b) 310,000 J added to the gas
52c)
53a) 40,000 J/s
53b) 160,000 J/s
53c) 220 s
55a) 7.7%
60) 70 K
61a) WADC = PA(VC – VA)
61b) WABC = PC(VC – VA)
61c) WAC = 1/2(PC + PA)(VC – VA)