2.1 Entropy as a State Function(3) S.J.T.U. Phase Transformation and Applications A.reversible B,irreversible -m Lost work Reversible work P2 82 Actual work V V V2 Volume Volume SJTU Thermodynamics of Materials Spring 2010 ©X.J.Jin Lecture 3 Second law IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2010 © X. J. Jin Lecture 3 Second law I 2.1 Entropy as a State Function(3) P1 P2 V1 V2 1 2 Pressure Volume Lost work Actual work P1 P2 V1 V2 1 2 Pressure Volume Reversible work    2 1 V V W PdV A, reversible B, irreversible