Solution Found!
A thermodynamic sys-tem is taken from state a to state c
Chapter 19, Problem 42P(choose chapter or problem)
A thermodynamic system is taken from state a to state c in Fig. P19.42 along either path abc or path adc. Along path abc, the work W done by the system is 450 J. Along path adc, W is 120 J. The internal energies of each of the four states shown in the figure are \(U_{a}=150 \mathrm{~J}\), \(U_{b}=240 \mathrm{~J}, \quad U_{c}=680 \mathrm{~J}\), and \(U_{d}=330 \mathrm{~J}\). Calculate the heat flow Q for each of the four processes ab, bc, ad, and dc. In each process, does the system absorb or liberate heat?
Questions & Answers
QUESTION:
A thermodynamic system is taken from state a to state c in Fig. P19.42 along either path abc or path adc. Along path abc, the work W done by the system is 450 J. Along path adc, W is 120 J. The internal energies of each of the four states shown in the figure are \(U_{a}=150 \mathrm{~J}\), \(U_{b}=240 \mathrm{~J}, \quad U_{c}=680 \mathrm{~J}\), and \(U_{d}=330 \mathrm{~J}\). Calculate the heat flow Q for each of the four processes ab, bc, ad, and dc. In each process, does the system absorb or liberate heat?
ANSWER:
Solution 42P This question is based on the first law of thermodynamics, which is expressed mathematically as Q = U + W , where Q is the amount of heat added to a system, U is the change in internal energy of the system and W is the work done by the system. Along path abc, W) abc = 450 J From path a to b, the volume remains constant, so W) = 0…..(1) ab So, W) = 450 J …..(2) bc Al