Keep the Heat B/Thermodynamics C

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Re: Keep the Heat B/Thermodynamics C

Post by AlvinXai » October 13th, 2011, 1:57 pm

Is rubber (synthetic or organic) a legal material for the insulating device?

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Re: Keep the Heat B/Thermodynamics C

Post by JSGandora » October 13th, 2011, 3:02 pm

Also, would cotton be granular?

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Re: Keep the Heat B/Thermodynamics C

Post by ichaelm » October 13th, 2011, 3:07 pm

Cotton is organic and fibrous, so it's legal. Rubber is neither granular or fibrous, so even if it's organic, it's illegal.

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Re: Keep the Heat B/Thermodynamics C

Post by JSGandora » October 13th, 2011, 6:07 pm

Thanks. Also, does dust affect the insulation? I'm worried about it because some of my materials may be old and be dusty (still haven't decided if I should use it). I think I read somewhere that dust affects the R-value because it muddles the air and it certainly affects house insulation.

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Re: Keep the Heat B/Thermodynamics C

Post by Frogger4907 » October 14th, 2011, 12:01 pm

chalker wrote:
Frogger4907 wrote: The rules don't state anything about measuring the temperature after you put the water in the beaker (for initial temperature). You can't take the temperature from the hot water bath do to heat lost during the transfer being an inconsistent variable. :?:

If you look closely at the scoring formulas, you'll note that none of them use 'initial temperature' for anything.
I see that now for the retention score because it is measured against the beaker not in the device. But looking at the prediction score, How are students supposed to have any possible way to accurately predict temperature without the temperature of the water after they have placed the beaker into the device? otherwise it will take a different amount of time to take the water from the bath and put it in the beaker, and put the beaker into the device, which will result in a different starting temperature. The heat lost during the transfer will be a huge variable in the starting temperature, because the water cools fairly quickly.
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Re: Keep the Heat B/Thermodynamics C

Post by chalker7 » October 14th, 2011, 12:23 pm

Frogger4907 wrote: I see that now for the retention score because it is measured against the beaker not in the device. But looking at the prediction score, How are students supposed to have any possible way to accurately predict temperature without the temperature of the water after they have placed the beaker into the device? otherwise it will take a different amount of time to take the water from the bath and put it in the beaker, and put the beaker into the device, which will result in a different starting temperature. The heat lost during the transfer will be a huge variable in the starting temperature, because the water cools fairly quickly.
The best answer to your question is simply to practice. If you take the trip from the water bath to your insulating device and the amount of time it takes to load the device into account (during which I think you won't necessarily lose that much heat) in your model, you should be able to accurately predict the final temperature. The starting temperature is not the temperature of the water when you put it into the device, it is the temperature of the water bath. Also, the time starts when you get the water....so it pays to practice the loading procedure and make sure you are consistent (and take account of multiple variables, such as ambient temperature in the room).

A lot of thought went into the procedure as written and it's the best mix of fairness to the students and ease of running for the event supervisors.
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Re: Keep the Heat B/Thermodynamics C

Post by Frogger4907 » October 14th, 2011, 3:47 pm

After a test I just completed, 50 mL of water heated to 83.84 degrees C In the time it took to measure and pour into the beakers and placed into the device took about 36 second the water had decreased in temperature 16.94 degrees Celsius, to 66.90 degrees. Now the rules do not state what kind device should be used for measuring so even the difference between a plastic and glass measuring device will make a difference. Plus the wording of the rules indicates that the supervisor will be measuring out the water. So the time it takes for the supervisor to measure the water will be different thus resulting in a different loss of heat for each team. Thus making prediction impossible without knowing the initial temperature. The amount of thought put into the procedure of the event may have been high, but none of it was from the students perspective. And having the students make a guess at the final temperature?? Obviously there are too many variables for that to happen. The procedures for this event should be completely re-written, this is not how Science Olympiad should be because scientists don't just throw out a slightly informed guess, they take accurate measurements and know things like the initial temperature!
Edit: It wouldn't make the event any harder to run if they had to measure the initial temperature!
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Re: Keep the Heat B/Thermodynamics C

Post by chalker » October 14th, 2011, 6:10 pm

Full disclosure: this post is going to be tl;dr for many of you. At a minimum I recommend skimming the last 2 paragraphs for the essence of this.
Frogger4907 wrote:After a test I just completed, 50 mL of water heated to 83.84 degrees C In the time it took to measure and pour into the beakers and placed into the device took about 36 second the water had decreased in temperature 16.94 degrees Celsius, to 66.90 degrees. Now the rules do not state what kind device should be used for measuring so even the difference between a plastic and glass measuring device will make a difference. Plus the wording of the rules indicates that the supervisor will be measuring out the water. So the time it takes for the supervisor to measure the water will be different thus resulting in a different loss of heat for each team.
36 seconds seems rather long to accomplish this. I suspect part of this is due to you trying to get exactly 50mL with some sort of 'scoop'. If I were running the event I'd use a ladle of appropriate volume to scoop up the precise amount of water everytime, which would significantly reduce the time to do this.

Regardless of that aspect, what's MORE important is whether or not what you just did is reproducible. Did you test it multiple times? What was the range of resulting temperatures? The rules explicitly don't ask for your temp prediction until the END of Part 1, prior to measuring the temp, in order to allow students time to perform calculations. Note the rules also explicitly state that the room temperature will be announced. I expect the best teams will bring stopwatches and time the period between when the water leaves the hot water bath and the beaker is enclosed, then incorporate that into their calculations.

Likewise, whether it's a plastic or glass measuring device could be incorporated into those calculations, although I suspect that will have minimal impact on the result.
Frogger4907 wrote: The amount of thought put into the procedure of the event may have been high, but none of it was from the students perspective.
This is completely untrue and somewhat hurtful. Many of us involved in the rules making (including myself and my brother) are former competitors and regularly take into account the students perspective. You aren't privy to the lengthy interactions we have over many months creating / updating rules, but I can assure you that we regularly say things like 'but is that the best thing for the students'.

From a personal standpoint, you have been an active member of these boards for about a year, so you should have noticed by now that I'm constantly soliciting input and feedback from board members, as well as the fact that I've mentioned how my involvement is a way to help 'pay it forward' to a cause that so significantly shaped my life.
Frogger4907 wrote: And having the students make a guess at the final temperature?? Obviously there are too many variables for that to happen. The procedures for this event should be completely re-written, this is not how Science Olympiad should be because scientists don't just throw out a slightly informed guess, they take accurate measurements and know things like the initial temperature!
Edit: It wouldn't make the event any harder to run if they had to measure the initial temperature!
Yes it would make it harder to run if they had to measure each teams individual temperature. For most event supervisors there will be only one probe, which means they'd have to run around, insert it in each device, check the temp, note the time, then try to time the process just right so that each team is given exactly the same amount of time until their device is measured for the final temp.

Regarding what scientists do, just they do 'throw out' informed guesses... informed to the best extent possible, based upon the data at hand. Part of Science Olympiad is exposing you to 'real world' type engineering and science problems, which are often constrained by things like resources and budgets. For every problem, there is always going to be a desire to have just a little more precise / detailed information, more time to do something, better equipment, etc etc.

That said, we are always open to suggestions / input. You suggest 'completely rewriting' the procedures for this event. Please provide us with a draft or specific changes to make and I'll be happy to discuss and consider them. Note the following considerations need to be kept in mind: they can't' be too long / detailed since we are limited to 2 pages in the rule book, they have to be able to be accomplished by the majority of event supervisors at the hundreds of regional tournaments (meaning no really expensive or complicated processes), and they have to allow for at a minimum of 10 teams to compete simultaneously in an hour long block.

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Re: Keep the Heat B/Thermodynamics C

Post by Frogger4907 » October 14th, 2011, 6:36 pm

chalker wrote: 36 seconds seems rather long to accomplish this. I suspect part of this is due to you trying to get exactly 50mL with some sort of 'scoop'. If I were running the event I'd use a ladle of appropriate volume to scoop up the precise amount of water everytime, which would significantly reduce the time to do this.

Regardless of that aspect, what's MORE important is whether or not what you just did is reproducible. Did you test it multiple times? What was the range of resulting temperatures? The rules explicitly don't ask for your temp prediction until the END of Part 1, prior to measuring the temp, in order to allow students time to perform calculations. Note the rules also explicitly state that the room temperature will be announced. I expect the best teams will bring stopwatches and time the period between when the water leaves the hot water bath and the beaker is enclosed, then incorporate that into their calculations.
Actually I just poured it to an approximation of 50 mL. but at the competition longer times will be needed to get more precise measurements, not to forget I was moving fairly quickly, To move quicker would be a safety flag, at temperatures between 70-80 degrees a 2nd to 3rd degree burn would occur within half of a second. and with the air temperature, In order to be precise we would have to do hundreds of trials in different temperatures, with different separations of when they are poured, how quickly they are poured, the difference of heat abortion by the glass beaker and a plastic measuring device, and the list goes on.
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Re: Keep the Heat B/Thermodynamics C

Post by Frogger4907 » October 14th, 2011, 6:45 pm

Frogger4907 wrote: The amount of thought put into the procedure of the event may have been high, but none of it was from the students perspective.
chalker wrote: This is completely untrue and somewhat hurtful. Many of us involved in the rules making (including myself and my brother) are former competitors and regularly take into account the students perspective. You aren't privy to the lengthy interactions we have over many months creating / updating rules, but I can assure you that we regularly say things like 'but is that the best thing for the students'.

From a personal standpoint, you have been an active member of these boards for about a year, so you should have noticed by now that I'm constantly soliciting input and feedback from board members, as well as the fact that I've mentioned how my involvement is a way to help 'pay it forward' to a cause that so significantly shaped my life.
Sorry for:
1. The double post.
2. And I'm tired this come out the way I had hoped, What I meant to imply was that there are many things that are hard to think about when you write the rules understandably, but as students start testing them flaws are revealed. Now the best thing for the students would be an event that cannot be run with inefficiencies, or inconsistencies such as the ones being revealed.
Now, I understand all the work that goes into the rules and I apologize for implying for anything that stated otherwise.
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