Thermodynamics B/C

User avatar
CookiePie1
Exalted Member
Exalted Member
Posts: 428
Joined: Thu Feb 15, 2018 5:05 pm
Division: C
State: NJ
Pronouns: He/Him/His
Has thanked: 121 times
Been thanked: 92 times

Re: Thermodynamics B/C

Post by CookiePie1 »

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?
South Brunswick High School Captain '22
2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD

Reality is merely an illusion, albeit a very persistent one.
-Albert Einstein
MattChina
Member
Member
Posts: 225
Joined: Sun Feb 12, 2017 8:06 am
Division: B
State: NY
Has thanked: 0
Been thanked: 0

Re: Thermodynamics B/C

Post by MattChina »

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?
2019 events: Water Quality, Battery Buggy, Elastic Launch Glider, Density Lab, Circuit Lab, Thermodynamics
R.C Murphy Co-Captain
Dank Memes Area Homeschool Team member
User avatar
Alex-RCHS
Member
Member
Posts: 539
Joined: Fri Nov 04, 2016 3:46 pm
Division: Grad
State: NC
Has thanked: 3 times
Been thanked: 1 time

Re: Thermodynamics B/C

Post by Alex-RCHS »

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.
About me!
Raleigh Charter HS (NC) 2018
UNC-Chapel Hill 2022
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: Sun Jan 18, 2015 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Thermodynamics B/C

Post by UTF-8 U+6211 U+662F »

CookiePie1 wrote:
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)
Vrund
Member
Member
Posts: 11
Joined: Fri May 19, 2017 8:06 pm
Has thanked: 0
Been thanked: 0

Re: Thermodynamics B/C

Post by Vrund »

For the Ice Water Bonus do they add the water to both the internal and external beakers or just the internal beaker?
UTF-8 U+6211 U+662F
Exalted Member
Exalted Member
Posts: 1597
Joined: Sun Jan 18, 2015 7:42 am
Division: C
State: PA
Has thanked: 6 times
Been thanked: 15 times

Re: Thermodynamics B/C

Post by UTF-8 U+6211 U+662F »

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
User avatar
Alex-RCHS
Member
Member
Posts: 539
Joined: Fri Nov 04, 2016 3:46 pm
Division: Grad
State: NC
Has thanked: 3 times
Been thanked: 1 time

Re: Thermodynamics B/C

Post by Alex-RCHS »

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.
About me!
Raleigh Charter HS (NC) 2018
UNC-Chapel Hill 2022
User avatar
CookiePie1
Exalted Member
Exalted Member
Posts: 428
Joined: Thu Feb 15, 2018 5:05 pm
Division: C
State: NJ
Pronouns: He/Him/His
Has thanked: 121 times
Been thanked: 92 times

Re: Thermodynamics B/C

Post by CookiePie1 »

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.
South Brunswick High School Captain '22
2020 Events: Protein Modeling, Ping Pong Parachute, Wright Stuff, Sounds of Music
2021 Events: Protein Modeling, Sounds of Music, Ornithology
2022 Events: TBD

Reality is merely an illusion, albeit a very persistent one.
-Albert Einstein
knightmoves
Member
Member
Posts: 500
Joined: Thu Apr 26, 2018 6:40 pm
Has thanked: 4 times
Been thanked: 84 times

Re: Thermodynamics B/C

Post by knightmoves »

CookiePie1 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?
User avatar
Alex-RCHS
Member
Member
Posts: 539
Joined: Fri Nov 04, 2016 3:46 pm
Division: Grad
State: NC
Has thanked: 3 times
Been thanked: 1 time

Re: Thermodynamics B/C

Post by Alex-RCHS »

knightmoves wrote:
CookiePie1 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.
About me!
Raleigh Charter HS (NC) 2018
UNC-Chapel Hill 2022

Return to “2018 Lab Events”