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Re: Keep the Heat B/Thermodynamics C
Posted: Wed Apr 04, 2012 7:59 pm
by siciscio
I don't know if this was mentioned before but what would be a better insulator: one with a low specific heat or a high specic heat?
If you were to use a material wouldn't you lose heat more rapidly than one with a higher specific heat. However with a material with a higher specific heat, would it absorb heat from the beaker?
so does this I mean I should use materials with high specific heat or low specific heat?
Thanks
Re: Keep the Heat B/Thermodynamics C
Posted: Thu Apr 05, 2012 5:46 am
by harryk
siciscio wrote:I don't know if this was mentioned before but what would be a better insulator: one with a low specific heat or a high specic heat?
If you were to use a material wouldn't you lose heat more rapidly than one with a higher specific heat. However with a material with a higher specific heat, would it absorb heat from the beaker?
so does this I mean I should use materials with high specific heat or low specific heat?
Thanks
Specific heat doesn't neccesarily correspond to insulative property, though you defintely want to avoid using materials with a high specific heat because they would absorb the heat from the beaker. Though a material with low specific heat isn't always a good insulator. What you want to know is the thermal conductivity of the material, here is a list on conductivities:
http://en.wikipedia.org/wiki/List_of_th ... uctivities
Re: Keep the Heat B/Thermodynamics C
Posted: Thu Apr 05, 2012 1:44 pm
by siciscio
harryk wrote:siciscio wrote:I don't know if this was mentioned before but what would be a better insulator: one with a low specific heat or a high specic heat?
If you were to use a material wouldn't you lose heat more rapidly than one with a higher specific heat. However with a material with a higher specific heat, would it absorb heat from the beaker?
so does this I mean I should use materials with high specific heat or low specific heat?
Thanks
Specific heat doesn't neccesarily correspond to insulative property, though you defintely want to avoid using materials with a high specific heat because they would absorb the heat from the beaker. Though a material with low specific heat isn't always a good insulator. What you want to know is the thermal conductivity of the material, here is a list on conductivities:
http://en.wikipedia.org/wiki/List_of_th ... uctivities
Ok. Thanks
Re: Keep the Heat B/Thermodynamics C
Posted: Mon Apr 09, 2012 1:27 pm
by JustDroobles
For state, with so many different levels of volume, temperature, and time, how did you test your device to collect data for accurate predictions? We have changed our device since regionals and have state on April 28th, and I am having difficulty coming up with a system to test my device to the precision I would need at state within only three weeks. What efficient systems have you developed for testing your devices?
Re: Keep the Heat B/Thermodynamics C
Posted: Mon Apr 09, 2012 2:09 pm
by Scipuppy
JustDroobles wrote:For state, with so many different levels of volume, temperature, and time, how did you test your device to collect data for accurate predictions? We have changed our device since regionals and have state on April 28th, and I am having difficulty coming up with a system to test my device to the precision I would need at state within only three weeks. What efficient systems have you developed for testing your devices?
We had a similar problem, we didn't finish until just before states, we ended up needing to bring the device home a lot. We did our calibrations for every 5 or 10 degrees, and every 10 mL. However, this takes a LOT of extra work. I would advise using a calculator that can connect to a probe, especially one that can record data so you don't need to do it by hand. This makes it a lot easier. I would start with just every 10 degrees and 10ml increments.
Re: Keep the Heat B/Thermodynamics C
Posted: Mon Apr 09, 2012 5:52 pm
by questionguy
I recently visted the Test Exchange and noticed that tests from the Athens Invitational were posted in most events, except for Thermodynamics. Does anyone have a copy of the test that they can post?
Re: Keep the Heat B/Thermodynamics C
Posted: Wed Apr 11, 2012 7:42 pm
by Science-dad
I have a question on rule interpretation. The rules for keep the heat are vey explicit about what can be done with the isulating device and the beaker within it. There is noticeable silence about the external non-insulated beaker. Can I infer that it would be consistent with the spirit of the rules to find or provide a relatively cool location for the external beaker near the device?
Re: Keep the Heat B/Thermodynamics C
Posted: Wed Apr 11, 2012 11:00 pm
by andrewwski
I would consider that to be against the spirit of the rules.
Re: Keep the Heat B/Thermodynamics C
Posted: Thu Apr 12, 2012 5:44 am
by harryk
Science-dad wrote:I have a question on rule interpretation. The rules for keep the heat are vey explicit about what can be done with the isulating device and the beaker within it. There is noticeable silence about the external non-insulated beaker. Can I infer that it would be consistent with the spirit of the rules to find or provide a relatively cool location for the external beaker near the device?
Well you can put your beaker anywhere on your table, but the temperature won't change that much in such a small area, and anything beyond that would definitely be against the spirit of the event
Re: Keep the Heat B/Thermodynamics C
Posted: Thu Apr 12, 2012 9:55 am
by Skink
And the reason most or all of us feel this way is because the only motivation you would have is to maximize the Heat Retention score, which can be construed as a way to cheat the system. Besides, A)most supervisors would not be likely to be open to this, anyways and B)there may not even be space other than the designated desk or lab bench, wherever the device is at.