p19_096.pdf

96. We note that there is no work done in process c

→

b , since there is no change of volume. We also note that

the magnitude of work done in process b

→

c is given, but not its sign (which we identify as negative as a

130)+ (+400)=

230 J. By the First Law of Thermodynamics (or, equivalently, conservation of energy), we have

19-8). The total (or net )heat transfer is Q net =(

−

40)+ (

−

Q net = W net

230 J = W a → c + W c → b + W b → a

= W a → c +0+(

−

80 J)

Therefore, W a → c = 310 J.

result of the discussion in