2013-3-1 0 Total Energy 2-15 Summary:Energy of a System In summary,the change in energy of a system from state 1 to state 2 is E2-E,=(U2-U)+(KE2-KE)+(PE2-PE) △E=△U+△KE+△PE Since an arbitrary value E can be assigned to the energy of a system at a given state 1,no particular significance can be attached to the value of energy at state 1 or any other state.Only changes in the energy of a system between states have significance. 2-16 8 2013-3-1 8 Total Energy 2-15 http://bcs.wiley.com/he-bcs/Books?action=index&itemId=0470918012&bcsId=6606 Summary: Energy of a System 2-16 ►In summary, the change in energy of a system from state 1 to state 2 is E2 – E1 = (U2 – U1) + (KE2 – KE1) + (PE2 – PE1) ΔE = ΔU + ΔKE + ΔPE ►Since an arbitrary value E1 can be assigned to the energy of a system at a given state 1, no particular significance can be attached to the value of energy at state 1 or any other state. Only changes in the energy of a system between states have significance