problem19_45

# University Physics with Modern Physics with Mastering Physics (11th Edition)

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19.45: We will need to use Equations (19.3), ( 29 . 4), - (17 and 1 2 W Q U V V p W - = - = a) The work done by the system during the process: Along ab or cd, W =0. Along bc, ( 29 ( 29 . , Along . a c a ad a c c bc V V p W ad V V p W - = - = b) The heat flow into the system during the process: . W U Q + = ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 ( 29 a c a a c adc a c a adc a c c a c a c c b c a b abc a c c abc d c dc d c dc a c a a d ad a d ad a c c b c bc b c bc a b ab a b ab V V p U U Q V V p W adc c a V V p U U V V p U U U U Q V V p W abc c a U U Q U U U V V p U U Q U U U V V p U U Q U U U U U Q U U U - + - = - = - + - = - + - + - = - = + - = - = - + - = - = - + - = - = + - = - = . : path along state to state From . : path along state to state From c) . 0 so , . so , . so , . 0 so , Assuming . and , , adc abc adc abc a c W W Q Q p p d) To understand this difference, start from the relationship . U
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Unformatted text preview: W Q ∆ + = The internal energy change U ∆ is path independent and so it is the same for path abc and path adc . The work done by the system is the area under the path in the pV-plane and is not the same for the two paths. Indeed, it is larger for path abc. Since U ∆ is the same and W is different, Q must be different for the two paths. The heat flow Q is path dependent....
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## This document was uploaded on 02/06/2008.

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