1.2 Energy Transfer(2) S.J.T.U. Phase Transformation and Applications Mechanical work W=FVI-F AVI-PanaVV A Resisting pressure □F(Force) multiplied by the change in volume Reversible:the initial state of the system can be restored with no observable effects in the system or the surroundings SJTU Thermodynamics of Materials Spring2010©X.J.Jin Lecture 1 First law I 18/38Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2010 © X. J. Jin Lecture 1 First law I 18/38 1.2 Energy Transfer (2) Mechanical work A l P V A F W F l      outside l F (Force) Reversible: the initial state of the system can be restored with no observable effects in the system or the surroundings Resisting pressure multiplied by the change in volume