## Thermodynamics B/C

UTF-8 U+6211 U+662F
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### Re: Thermodynamics B/C

wec01 wrote:
UTF-8 U+6211 U+662F wrote:How much work is done on a gas that is isothermally compressed to half its original size at a temperature of 40 degrees Réaumur?
`- nRTln(V[math]_2[/math]/V[math]_1[/math]) = - n * 8.314 J/(mol*K) * 40 °Ré * ln (1/2) = - n * 8.314 J/(mol*K) * 323 K * ln (1/2) = [b]1860 J/mol[/b]`
Oops I forgot to specify an amount. Yes, that's correct, your turn.

wec01
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### Re: Thermodynamics B/C

1) What is this device known as?
2) Who is generally credited with creating it?
3) What is it supposed to measure? What other variable affects the fluid level?
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2nd place Thermodynamics

mjcox2000
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### Re: Thermodynamics B/C

wec01 wrote:
1) What is this device known as?
2) Who is generally credited with creating it?
3) What is it supposed to measure? What other variable affects the fluid level?
```Thermoscope
Galileo
It’s supposed to measure temperature, but pressure affects it too.```
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wec01
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### Re: Thermodynamics B/C

mjcox2000 wrote:
wec01 wrote:
1) What is this device known as?
2) Who is generally credited with creating it?
3) What is it supposed to measure? What other variable affects the fluid level?
```Thermoscope
Galileo
It’s supposed to measure temperature, but pressure affects it too.```
2019 Division C Nationals Medals:
4th place Fossils
5th place Sounds of Music
2nd place Thermodynamics

mjcox2000
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### Re: Thermodynamics B/C

A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
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wec01
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### Re: Thermodynamics B/C

mjcox2000 wrote:A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
```1. 300 K
2. 4 kJ
3. 3 kJ
4. 75%```
2019 Division C Nationals Medals:
4th place Fossils
5th place Sounds of Music
2nd place Thermodynamics

mjcox2000
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### Re: Thermodynamics B/C

wec01 wrote:
mjcox2000 wrote:A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
```1. 300 K
2. 4 kJ
3. 3 kJ
4. 75%```
Nope. Try again!
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UTF-8 U+6211 U+662F
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### Re: Thermodynamics B/C

mjcox2000 wrote:A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
I'm confused how the reservoirs could reach equilibrium? The Carnot cycle assumes that the reservoirs will never change temperature.

mjcox2000
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### Re: Thermodynamics B/C

UTF-8 U+6211 U+662F wrote:
mjcox2000 wrote:A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
I'm confused how the reservoirs could reach equilibrium? The Carnot cycle assumes that the reservoirs will never change temperature.
The Carnot cycle doesn’t require constant-temperature reservoirs.
`The Carnot efficiency equation predicts the instantaneous efficiency. Try integrating.`
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wec01
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### Re: Thermodynamics B/C

mjcox2000 wrote:
UTF-8 U+6211 U+662F wrote:
mjcox2000 wrote:A hot and cold reservoir are used to convert heat to work in a Carnot cycle. The hot reservoir starts at 400K and has a heat capacity of 40 J/K, and the cold reservoir starts at 100K and has a heat capacity of 20 J/K. The Carnot cycle runs until the reservoirs are in thermal equilibrium.

1. At what temperature do the reservoirs reach equilibrium?
2. How much heat does the hot reservoir lose in the course of this process?
3. How much energy (i.e. work) does the Carnot cycle capture in the course of this process?
4. What is the total efficiency of this process?
I'm confused how the reservoirs could reach equilibrium? The Carnot cycle assumes that the reservoirs will never change temperature.
The Carnot cycle doesn’t require constant-temperature reservoirs.
`The Carnot efficiency equation predicts the instantaneous efficiency. Try integrating.`
```1. 252 K
2. 5920 J
3. 2880 J
4. 48.6 %```
2019 Division C Nationals Medals:
4th place Fossils
5th place Sounds of Music
2nd place Thermodynamics

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