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Re: Thermodynamics B/C

Posted: November 7th, 2017, 1:14 pm
by WhatScience?
arv101 wrote:Wow this is great thanks for organizing, can we stay anonuymus in the test and should I email you the questions.
Yes and Yes

Re: Thermodynamics B/C

Posted: November 7th, 2017, 3:22 pm
by arv101
Also can we make this like a complete event run, so predictions and you randomly pick the volume and start temperature, so we get a heat score. This is because I also want to see how I rank overall so not just the test. If you want to do that later on, if it is too early that would be good too.

Re: Thermodynamics B/C

Posted: November 8th, 2017, 5:11 am
by WhatScience?
arv101 wrote:Also can we make this like a complete event run, so predictions and you randomly pick the volume and start temperature, so we get a heat score. This is because I also want to see how I rank overall so not just the test. If you want to do that later on, if it is too early that would be good too.
I would honestly prefer to do that a bit later as I want more time to test my device and improve it. I imagine other people are in the same scenario.

Re: Thermodynamics B/C

Posted: November 8th, 2017, 9:52 am
by EastStroudsburg13
kendreaditya wrote:
WhatScience? wrote:
kendreaditya wrote:
I bought aerogel early in the year cause I was a noob so... also it's not that expensive ($20).

What design are you using?
Where did you buy your aerogel from?

As for my design...I don't feel comfortable posting the exact thing on the internet (just like in the build forums how nobody posts a winning design) however I can give you answers to any specific questions if you have them.
Not to pressure you, but people do share their designs on the building forms. I did scrambler last year, placed 3rd at states. Why? because people shared their ideas and designs.

People do publish the winning designs:
https://scioly.org/wiki/index.php/The_Best_of_2017
Do note that this wiki page only contains images of designs that were for last season, and such images were only posted after nationals occurred. There are, of course, cases of users describing their devices on the forums before they were done competing, and describing one's design is different than showing an exact picture of the design, but I wanted to clarify the purpose of the Best Of page.

Re: Thermodynamics B/C

Posted: November 8th, 2017, 10:53 am
by Alex-RCHS
WhatScience? wrote:
arv101 wrote:Also can we make this like a complete event run, so predictions and you randomly pick the volume and start temperature, so we get a heat score. This is because I also want to see how I rank overall so not just the test. If you want to do that later on, if it is too early that would be good too.
I would honestly prefer to do that a bit later as I want more time to test my device and improve it. I imagine other people are in the same scenario.
I agree. Also, there’s no need to compare build scores in this way because people often voluntarily post what they have been getting.

Re: Thermodynamics B/C

Posted: November 8th, 2017, 12:19 pm
by arv101
True

Re: Thermodynamics B/C

Posted: November 10th, 2017, 7:56 am
by samuel.barlow003
Can we use expanded polystyrene?

Re: Thermodynamics B/C

Posted: November 10th, 2017, 9:52 am
by Alex-RCHS
samuel.barlow003 wrote:Can we use expanded polystyrene?
Of course. The only prohibited materials are listed in the rules.

Re: Thermodynamics B/C

Posted: November 10th, 2017, 2:32 pm
by WhatScience?
Hey guys...I was solving a thermo test and came across this question:

If Th = 30°C and Tc =230°C, what is the maximum efficiency?

I used the equation 1 - Tcold/Thot and I got 0.87 (rounded) which was one of the answer choices. The correct answer however was 0.40.

Can anyone explain this to me (or attach a link that does?)

(Or is it that the answer key was wrong?)

Re: Thermodynamics B/C

Posted: November 10th, 2017, 3:16 pm
by Alex-RCHS
WhatScience? wrote:Hey guys...I was solving a thermo test and came across this question:

If Th = 30°C and Tc =230°C, what is the maximum efficiency?

I used the equation 1 - Tcold/Thot and I got 0.87 (rounded) which was one of the answer choices. The correct answer however was 0.40.

Can anyone explain this to me (or attach a link that does?)

(Or is it that the answer key was wrong?)
You should use degrees Kelvin for calculations like this.