1st law of thermodynamics


Registered Senior Member
Sears and Salinger develops the concept of 1st law of thermodynamics by stating that workdone along all adiabatic paths between two eqlbm. states(in same KE & PE) are the same iff dissipative work does not change the configuration of the system.From this,they claims the existence of a state property called internal energy of the system which is essentially an exact differential.It is given by
dU=-d'(W_ad) where W_ad means workdone in adiabatic path.
This much is OK.Now,they define heat flow Q into the system as Q=W-W_ad where W is the total work.
What do they mean by the 'total work'?I suppose,thie total work includes:
1.configuration work;be it reversible,irreversible,free expansion etc.
2.Dissipative work;at constant configuration,or changing the configuration.
Specifically,I am interested in the bold typed case mentioned last of all.Please let me know if I am correct.
I suppose it's exactly what it sounds like, the total work or energy via the Work-Energy Theorem inside the closed system.