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Re: Thermodynamics B/C

Posted: April 11th, 2018, 3:30 pm
by UTF-8 U+6211 U+662F
JoeyC wrote:When doing pressure equations with the pressure initially given in Pascals, for our answers would we use Pascals or Atms; I had a question as the such given to me which asked for hydro static pressure, with the external pressure given in Pascals. Answered with Pascals, but still don't know if I got the question right as it was a regional, and the tests have not (and might not ever) be released.
You should probably just use it in terms of units they give you. If in doubt, go with the SI unit (though a good test would accept both).

Re: Thermodynamics B/C

Posted: April 11th, 2018, 6:46 pm
by CookiePie1
UTF-8 U+6211 U+662F wrote:
JoeyC wrote:When doing pressure equations with the pressure initially given in Pascals, for our answers would we use Pascals or Atms; I had a question as the such given to me which asked for hydro static pressure, with the external pressure given in Pascals. Answered with Pascals, but still don't know if I got the question right as it was a regional, and the tests have not (and might not ever) be released.
You should probably just use it in terms of units they give you. If in doubt, go with the SI unit (though a good test would accept both).
What do you mean by 'good test'?

Re: Thermodynamics B/C

Posted: April 11th, 2018, 6:50 pm
by TheChiScientist
Means a fair test that is run by a competent ES would count it for points. Right?

Re: Thermodynamics B/C

Posted: April 11th, 2018, 7:29 pm
by arv101
Yeah also I am pretty sure you are supposed to use SI units unless stated otherwise according to the rules.

Re: Thermodynamics B/C

Posted: April 12th, 2018, 8:39 am
by TheChiScientist
Yea it is rare but there are tests that require a different non SI unit

Re: Thermodynamics B/C

Posted: April 12th, 2018, 3:26 pm
by UTF-8 U+6211 U+662F
atm, Torr, and mmHg are also units that are used fairly often in the SI system to describe pressure, so all of them should be acceptable. Unfortunately not always the case.

Re: Thermodynamics B/C

Posted: April 15th, 2018, 11:35 am
by jinhusong
I was helping Thermodynamics B in Northern California State yesterday. It is my first time take part in this event. Here are some thoughts I hope can help students improve the score.

The beaker, prefer better heat conductivity ones. So glass is better than plastic. thinner is better than thicker. If you think it does not matter, think again, like go to the extreme, assume both your beaker already have very high isolation.

Beaker bottom plat is better so that the outside one have better contact with the table normally better heat conductivity and capacity.

Please study the rules. Many many groups only have charts with 7 points. Rule asked at least 10 points.

If your device exceeds the size limit with the lid, try cut it or take the lid off so your device will not be put into tier 2.

Best wishes and good luck.

Re: Thermodynamics B/C

Posted: April 15th, 2018, 1:31 pm
by Alex-RCHS
For those who have gone to lots of competitions, is the ice bonus normally administered so that you can measure the temperature of the water in the beaker immediately after adding the cold water? That's what I imagine it is, but the rules aren't super clear.

Re: Thermodynamics B/C

Posted: April 15th, 2018, 4:36 pm
by TheChiScientist
Ikr that part is vague but I have rarely seen this in action cuz no one goes for the IWB.
Still, I feel like that part of the rules depends on your ES cuz some don't allow it.

Re: Thermodynamics B/C

Posted: April 16th, 2018, 10:58 pm
by Vrund
Had a question about the way thermo would be ran at nationals? So for the initial temperature of the water would it be measured before it is poured into the internal beaker or after? (cuz I've seen it be measured before at invitationals but would just like to make sure) and then for the ice water bonus do you get to know the initial temperature after the ice water is added?