Questions and Answers S.J.T.U. Phase Transformation and Applications 0=dU CydT dU =CydT V1,T1 V2,T2 dU=CdT dU =0 Ideal gas V1,T2 20 atm 10 atm 20 atm 50L 50L ?L 10 atm 25℃ 25C 50L Adiabatic ? expansion SJTU Thermodynamics of Materials Spring2006©X.J.Jimn Lecture 3 Second law IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2006 © 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 = V dTCdU dTCdUQ = V dTCdU δ = = V 20 atm 50 L 25 °C 10 atm 50 L ? 10 atm 50 L ? 20 atm ? L 25 °C Adiabatic expansion