Thermodynamics B/C

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

Post by UTF-8 U+6211 U+662F » March 4th, 2019, 12:31 pm

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.

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Re: Thermodynamics B/C

Post by wec01 » March 5th, 2019, 2:57 pm

Image
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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Re: Thermodynamics B/C

Post by mjcox2000 » March 8th, 2019, 7:16 pm

wec01 wrote:Image
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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Re: Thermodynamics B/C

Post by wec01 » March 9th, 2019, 6:06 am

mjcox2000 wrote:
wec01 wrote:Image
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.
Yep, your turn
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2nd place Thermodynamics

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Re: Thermodynamics B/C

Post by mjcox2000 » March 12th, 2019, 7:33 pm

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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Re: Thermodynamics B/C

Post by wec01 » March 13th, 2019, 6:11 pm

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%
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4th place Fossils
5th place Sounds of Music
2nd place Thermodynamics

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Re: Thermodynamics B/C

Post by mjcox2000 » March 14th, 2019, 4:16 am

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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Re: Thermodynamics B/C

Post by UTF-8 U+6211 U+662F » April 15th, 2019, 2:39 pm

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.

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Re: Thermodynamics B/C

Post by mjcox2000 » April 16th, 2019, 3:11 am

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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Re: Thermodynamics B/C

Post by wec01 » April 16th, 2019, 8:08 pm

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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