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Re: Keep the Heat B/Thermodynamics C

Posted: April 10th, 2013, 5:31 pm
by maggeey
istou wrote:
maggeey wrote:Does anyone know if we can use tinfoil in our keep the heat boxes? I saw a whole bunch of teams with it or some other reflective stuff at regionals. I think it might help me if I could use it.
To make it simple - you can use reflecting foils, their very useful.
[/quote]

Thanks istou, this is my first time on this event. I just looked it up and aluminum is a metal, so I'm thinking I can't use tin foil. Is there reflecting foils that aren't plastic or metal we can use?

Re: Keep the Heat B/Thermodynamics C

Posted: April 10th, 2013, 6:06 pm
by hmcginny
maggeey wrote:
istou wrote:
maggeey wrote:Does anyone know if we can use tinfoil in our keep the heat boxes? I saw a whole bunch of teams with it or some other reflective stuff at regionals. I think it might help me if I could use it.
To make it simple - you can use reflecting foils, their very useful.
Thanks istou, this is my first time on this event. I just looked it up and aluminum is a metal, so I'm thinking I can't use tin foil. Is there reflecting foils that aren't plastic or metal we can use?
Note that the words metal and plastic are in parentheses in reference to foams. That means no metal foams, plastic foams etc... not that you can't use metal or plastic. Aluminum/tin foil is fine to use.

Re: Keep the Heat B/Thermodynamics C

Posted: April 10th, 2013, 6:32 pm
by istou
maggeey wrote:
istou wrote:
maggeey wrote:Does anyone know if we can use tinfoil in our keep the heat boxes? I saw a whole bunch of teams with it or some other reflective stuff at regionals. I think it might help me if I could use it.
To make it simple - you can use reflecting foils, their very useful.
Thanks istou, this is my first time on this event. I just looked it up and aluminum is a metal, so I'm thinking I can't use tin foil. Is there reflecting foils that aren't plastic or metal we can use?[/quote]

You can use standard aluminum folder you can buy at any supermarket. Make sure a beaker does not see any not foiled area. Minimize amount of air around the beaker. Make sure you have 2-3 layers of cardboard or some other insulator above the beaker and keep the 1.5 cm hole open. Add some bids under the beaker.
We got one 1st and two 3d places with our thermos at world toughest competition.

Re: Keep the Heat B/Thermodynamics C

Posted: April 10th, 2013, 8:00 pm
by maggeey
You can use standard aluminum folder you can buy at any supermarket. Make sure a beaker does not see any not foiled area. Minimize amount of air around the beaker. Make sure you have 2-3 layers of cardboard or some other insulator above the beaker and keep the 1.5 cm hole open. Add some bids under the beaker.
We got one 1st and two 3d places with our thermos at world toughest competition.[/quote]

Okay, thanks.

Re: Keep the Heat B/Thermodynamics C

Posted: April 12th, 2013, 5:50 pm
by ScienceOlympian
Any topics I should study for state? Other than the rules.
What thermodynamic formulas are needed?
Any good sites?
Any specific sites on the history of Thermodynamics?

Re: Keep the Heat B/Thermodynamics C

Posted: April 12th, 2013, 5:54 pm
by mrburrito
You should study some history, and the little things like engines. It's helpful to know math because those are often worth more or they're tiebreaker questions. Bernoulli's equation and many conservation formulas are good to know. I don't know too many sites, but if you can get your hands on a thermodynamics textbook, they have literally everything in them. I hope this is helpful.

Re: Keep the Heat B/Thermodynamics C

Posted: April 12th, 2013, 7:25 pm
by FullMetalMaple
ScienceOlympian wrote:Any topics I should study for state? Other than the rules.
What thermodynamic formulas are needed?
Any good sites?
Any specific sites on the history of Thermodynamics?
I got my formulas from my AP Chem and AP Physics textbooks, but most of them might be a bit high-level for div B. For other resources, check the Thermodynamics Wiki and this online textbook.

As for history, there's some info here. It's a bit short but enough to get you started.

Re: Keep the Heat B/Thermodynamics C

Posted: April 13th, 2013, 8:56 am
by Cheesy Pie
I use the four thermo chapters in my physics textbook and the Internet. XD

Re: Keep the Heat B/Thermodynamics C

Posted: April 14th, 2013, 9:20 am
by sjwon3789
According to http://www.virginiaso.org/pdf/VASO_Even ... cement.pdf, does that mean I'm not given the extra 5 minutes provided for keep the heat?, which states: iii. Teams must be given 5 minutes to setup/modify their devices at the start of the competition. Devices that do not meet the construction specs must not be allowed to be tested until brought into spec.

<I have also posted this in my state page>

Also, is it worse if the beaker is touching the aluminium foil or any other insulators? Is it better to leave gap around the beaker? (If so, small or big?)

Re: Keep the Heat B/Thermodynamics C

Posted: April 14th, 2013, 6:56 pm
by Schrodingerscat
sjwon3789 wrote:According to http://www.virginiaso.org/pdf/VASO_Even ... cement.pdf, does that mean I'm not given the extra 5 minutes provided for keep the heat?, which states: iii. Teams must be given 5 minutes to setup/modify their devices at the start of the competition. Devices that do not meet the construction specs must not be allowed to be tested until brought into spec.

<I have also posted this in my state page>

Also, is it worse if the beaker is touching the aluminium foil or any other insulators? Is it better to leave gap around the beaker? (If so, small or big?)
My outsider interpretation: that policy is referring to exceptions to the rules for lower levels of competition, not to the rules itself. It is normal for building events to give time to modify devices prior to running, and I think the intent of the second part of that rule is so that a team cannot abuse the penalty for construction violations (eg intentionally break a rule to get 15 more points and only lose 10 points to penalties).

However, if you are concerned, I would recommend forwarding this question for clarification through the proper official channels (most likely your school's coach should contact the appropriate person in your state).