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phy131studiof15:lectures:finalreview1 [2015/12/01 22:43]
mvfernandezserra [First Law of Thermodynamics]
phy131studiof15:lectures:finalreview1 [2015/12/02 08:52] (current)
mvfernandezserra old revision restored (2015/11/30 10:54)
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 The [[http://​en.wikipedia.org/​wiki/​First_law_of_thermodynamics|first law of thermodynamics]],​ dictates how internal energy, heat and work are related to each other. For a closed system the first law states that the change in the internal energy of a system, $\Delta E_{int}$, is the sum of the heat added **to** the system $Q$ and the net work done **by** the system $W$. The [[http://​en.wikipedia.org/​wiki/​First_law_of_thermodynamics|first law of thermodynamics]],​ dictates how internal energy, heat and work are related to each other. For a closed system the first law states that the change in the internal energy of a system, $\Delta E_{int}$, is the sum of the heat added **to** the system $Q$ and the net work done **by** the system $W$.
  
-$\Delta E_{int}=Q+W$. With this definition the work done by the gas is $W=-\int{PdV}$. This is the same as saying $\Delta E_{int}=Q-W$ and define $W=\int{PdV}$+$\Delta E_{int}=Q-W$
  
-The table shows some of the results that apply to a particular kind of thermal process. I use the definition $\Delta E_{int}=Q+W$ and $W=-\int{PdV}$.+The table shows some of the results that apply to a particular kind of thermal process
  
 ^Process^Constant<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​^ΔE<​sub>​int</​sub>​^Q^W^ ^Process^Constant<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​^ΔE<​sub>​int</​sub>​^Q^W^
-| Isothermal | T | 0 | Q=-W | W=-Q | +| Isothermal | T | 0 | Q=W | W=Q | 
-| Isobaric | P | Q-PΔV<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | ΔE<​sub>​int</​sub>​+PΔV<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | -PΔV |+| Isobaric | P | Q-PΔV<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | ΔE<​sub>​int</​sub>​+PΔV<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | PΔV |
 | Isovolumetric<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | V | Q | ΔE<​sub>​int</​sub>​ | 0 | | Isovolumetric<​html>&​nbsp;&​nbsp;&​nbsp;&​nbsp;</​html>​ | V | Q | ΔE<​sub>​int</​sub>​ | 0 |
-| Adiabatic || W | 0 | ΔE<​sub>​int</​sub>​ |+| Adiabatic || -W | 0 | -ΔE<​sub>​int</​sub>​ |
  
 ===== Path dependence of the work ===== ===== Path dependence of the work =====
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 $e=1-\frac{T_{L}}{T_{H}}$ $e=1-\frac{T_{L}}{T_{H}}$
  
-Note: f=number of degrees of freedom. f=3 for monoatomic gas and f=5 for diatomic gas. 
- 
-^Segment^Constant^$\Delta E$^Q^W^ 
-| A-B | T | 0 | Q=-W | W=$nRTln(V_A/​V_B)$ | 
-| B-C | None | $\frac{f}{2}nR(T_c-T_B)$ | 0 | $\Delta E$| 
-| C-D | T | 0 | Q=-W | W=$nRTln(V_C/​V_D)$ | 
-| D-A | None | $\frac{f}{2}nR(T_A-T_D)$ | 0 | $\Delta E$| 
  
 ===== What is Entropy? ===== ===== What is Entropy? =====
phy131studiof15/lectures/finalreview1.txt · Last modified: 2015/12/02 08:52 by mvfernandezserra
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