- #1
Sabian
- 13
- 0
Homework Statement
One body of constant pressure heat capacity [itex]C_P[/itex] at temperature [itex]T_i[/itex] it's placed in contact with a thermal reservoir at a higher temperature [itex]Tf[/itex]. Pressure is kept constant until the body achieves equilibrium with the reservoir.
a) Show that the variation in the entropy of the universe equals:
[itex]C_P [x − ln(1 + x )][/itex],
onde [itex]x = − \frac {(Tf− Ti )}{Tf}[/itex]
(There might be some translation issues from Portuguese to English).
Homework Equations
All I can think is
[itex]C_P= T \left ( \frac {\partial S}{\partial T} \right )_P [/itex]
[itex] dU = T dS [/itex]
[itex] dQ = C_P dT [/itex]
[itex] dS = \frac {dQ}{T} [/itex]
The Attempt at a Solution
I haven't been able to understand the underlying physics properly. I attempted a "no idea what I'm doing but here I go" with the first equation, which led to nothing. I assume that the entropy variation of the universe should be the addition of the variation in the body and in the reservoir but can't seem to calculate them correctly.Thank you for your time people.