Condition of equilibrium S.J.T.U. Phase Transformation and Applications Two states are in equilibrium when no reversible work can be done by having the system change between those two states 2 OWrer.12 =0 MA Figure 4.1 Machine MA to trans- form mass m from state I to state 2. The temperatures in the two states must be equal .A consequence of the second law of thermodynamics Otherwise... SJTU Thermodynamics of Materials Spring2007©X.J.Jin Lecture 7 equilibrium IPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2007 © X. J. Jin Lecture 7 equilibrium I Condition of equilibrium • Two states are in equilibrium when no reversible work can be done by having the system change between those two states δWrev →21. = 0 • The temperatures in the two states must be equal •A consequence of the second law of thermodynamics •Otherwise…