Questions and Answers S.J.T.0. Phase Transformation and Applications 80=dU=CvdT dU=CdT V1,T1 V2,T2 d CdT dU =0 Ideal gas V1,T2 =0 20 atm 10 atm 20 atm 50L 50L ?L 10 atm 25C 25℃ 50L Adiabatic ? expansion SJTU Thermodynamics of Materials Fall 2012 ©X.J.Jin Lecture 3 Second law IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2012 © X. J. Jin Lecture 3 Second law I Questions and Answers V1,T1 V2,T2 V1,T2 dU = 0 Ideal gas ⎟ = 0 ⎠⎞ ⎜⎝⎛ ∂∂V T U dU = CV dT Q dU C dT dU = CV dT δ = = V 20 atm 50 L 25 °C 10 atm 50 L ? 10 atm 50 L ? 20 atm ? L 25 °C Adiabatic expansion