Re: [Phys-L] work versus mechanical transfer of energy

[Diego Saravia <dsa@unsa.edu.ar>]

> Consider the equation
>
>          dE =  T ds   -   P dV                       [1a]


I  use in that eq dU as internal energy not dE or energy

gravitational energy is outside dU

that equation is only valid for  a path complete developed through
equilibrium states and  in a reversible process, of course in systems with
that variables and no others.

Its clearlly not the general universal first law. Its only for that kind of
systems. And is more than the fist law for that systems.



> Furthermore, it is usually a mistake to focus on «heat» and
> «work» anyway.  If in doubt, if there is even the slightest
> risk of confusion, forget about those concepts and instead
> focus on energy and entropy.



how can you introduce mechanical energy without work definition?



-- 
Diego Saravia
Diego.Saravia@gmail.com
NO FUNCIONA->dsa@unsa.edu.ar