The first law of thermodynamics

The first law of thermodynamics gives the quantiative relations between the internal energy of a system and the quantities of heat and work that the system exchange with surroundings. It express the conservation of energy. The first law of thermodynamics is true, but not enough ! Why ? Many thermodynamic processes which don’t violate the 1st law, but don’t happen in nature !

31p thanhan 22-07-2009 215 44   Download

 We knew that the concepts of mechanical work and energy play an important role in studying mechanical phenomena.  Concerning to thermal phenomena, there exits a new form of energy called “heat”: Heat can be transferred from one to other systems For a system with volume held constant, the effect of heat is to change the temparature of a system.

27p thanhan 22-07-2009 211 44   Download