## Thermodynamics B/C

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### Re: Thermodynamics B/C

Justin72835 wrote:
kickit wrote:Hello,
Does anyone know the answer to this question? I have no idea how to solve it, and I don't know calculus.

Two identical rooms are at 15 C and 25 C respectively. They are separated by an aluminum wall of thickness 0.5 m and area 10 m2. Assume the rooms are isolated from the rest of the world. The thermal conductivity coefficient of aluminum is 237 W m-1K-1

(4 Points) After a long time, what temperature will the rooms come to, at equilibrium? (For this part, assume the aluminum wall in between the rooms is negligible)

(20 Points) How long will it take for the rooms to come within 5 C of each other? Show work.
Here's an alternate solution! One thing I love about calc problems is how versatile they are in how you can approach them.
```[img]https://i.imgur.com/NOxAV7B.jpg[/img]
Also, sorry for using n-solve at the very end lol.```
It appears to me that you all are in div. C. My question is, Did you guys all take calculus before? And how would I, in div. B be able to solve these kinds of problems without having a background in physics or calc?
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### Re: Thermodynamics B/C

Justin72835 wrote:
kickit wrote:Hello,
Does anyone know the answer to this question? I have no idea how to solve it, and I don't know calculus.

Two identical rooms are at 15 C and 25 C respectively. They are separated by an aluminum wall of thickness 0.5 m and area 10 m2. Assume the rooms are isolated from the rest of the world. The thermal conductivity coefficient of aluminum is 237 W m-1K-1

(4 Points) After a long time, what temperature will the rooms come to, at equilibrium? (For this part, assume the aluminum wall in between the rooms is negligible)

(20 Points) How long will it take for the rooms to come within 5 C of each other? Show work.
Here's an alternate solution! One thing I love about calc problems is how versatile they are in how you can approach them.
```[img]https://i.imgur.com/NOxAV7B.jpg[/img]
Also, sorry for using n-solve at the very end lol.```
I was just wondering, do u need calculus to solve this problem?
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### Re: Thermodynamics B/C

Justin72835 wrote:
kickit wrote:Hello,
Does anyone know the answer to this question? I have no idea how to solve it, and I don't know calculus.

Two identical rooms are at 15 C and 25 C respectively. They are separated by an aluminum wall of thickness 0.5 m and area 10 m2. Assume the rooms are isolated from the rest of the world. The thermal conductivity coefficient of aluminum is 237 W m-1K-1

(4 Points) After a long time, what temperature will the rooms come to, at equilibrium? (For this part, assume the aluminum wall in between the rooms is negligible)

(20 Points) How long will it take for the rooms to come within 5 C of each other? Show work.
Here's an alternate solution! One thing I love about calc problems is how versatile they are in how you can approach them.
```[img]https://i.imgur.com/NOxAV7B.jpg[/img]
Also, sorry for using n-solve at the very end lol.```
Very cool! I also love that there’s more than one way to solve them.
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UNC-Chapel Hill 2022

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### Re: Thermodynamics B/C

Justin72835 wrote:
kickit wrote:Hello,
Does anyone know the answer to this question? I have no idea how to solve it, and I don't know calculus.

Two identical rooms are at 15 C and 25 C respectively. They are separated by an aluminum wall of thickness 0.5 m and area 10 m2. Assume the rooms are isolated from the rest of the world. The thermal conductivity coefficient of aluminum is 237 W m-1K-1

(4 Points) After a long time, what temperature will the rooms come to, at equilibrium? (For this part, assume the aluminum wall in between the rooms is negligible)

(20 Points) How long will it take for the rooms to come within 5 C of each other? Show work.
Here's an alternate solution! One thing I love about calc problems is how versatile they are in how you can approach them.
```[img]https://i.imgur.com/NOxAV7B.jpg[/img]
Also, sorry for using n-solve at the very end lol.```
It appears to me that you all are in div. C. My question is, Did you guys all take calculus before? And how would I, in div. B be able to solve these kinds of problems without having a background in physics or calc?
You shouldn't have calc questions on a B div test (and generally, calc questions shouldn't be on C div tests either)

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### Re: Thermodynamics B/C

For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?

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### Re: Thermodynamics B/C

Vrund wrote:For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
Just internal

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### Re: Thermodynamics B/C

Vrund wrote:For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
Just internal.
Edit: oops.
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### Re: Thermodynamics B/C

Vrund wrote:For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
Just the internal, which is why I think it's not really worth it.
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### Re: Thermodynamics B/C

Vrund wrote:For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
Just the internal, which is why I think it's not really worth it.
If you added ice water to both beakers, it would be obviously right to add the max all the time. There'd be nothing to think about.

As it is, try the ice water bonus. You know how your device scores without ice water. Try it with, and pretend you're competing with yourself without the ice. Who wins?

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### Re: Thermodynamics B/C

knightmoves wrote:
Vrund wrote:For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
Just the internal, which is why I think it's not really worth it.
If you added ice water to both beakers, it would be obviously right to add the max all the time. There'd be nothing to think about.

As it is, try the ice water bonus. You know how your device scores without ice water. Try it with, and pretend you're competing with yourself without the ice. Who wins?
I have really strong opinions about the ice bonus, and I agree with this. Here is what I know:
1. We tested ice bonus vs. not ice bonus at various times, temps, and volumes. We found the ice bonus to “beat” the non ice bonus every time.
2. At states our device performed equally or better than every non-ice bonus team.
3. Our prediction at nats was only 0.1 degrees off. And this was not a surprise.
4. Troy used the ice bonus.