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Re: Thermodynamics B/C Build
Posted: February 5th, 2019, 5:36 pm
by ElPotato
CookiePie1 wrote:TheChiScientist wrote:CaTaStRoPhY wrote:
Ooooh okay. So no matter what, my equation should work, right? I mean transferring water from one container to another shouldn't matter right?
Well to a degree. You have heat loss and then that heat loss increases to a point when water is transferred multiple times. So it can depend on the situation.
I still don't believe in equations and I say it's better to just go based on trials. It might work, but it probably won't...
I agree, I've always used trials. Equations assume that your box is pretty ideal, and imo they don't take into account all the random discrepancies that can occur during competition.
Re: Thermodynamics B/C Build
Posted: February 5th, 2019, 5:53 pm
by CaTaStRoPhY
CPScienceDude wrote:CookiePie1 wrote:TheChiScientist wrote:
Well to a degree. You have heat loss and then that heat loss increases to a point when water is transferred multiple times. So it can depend on the situation.
I still don't believe in equations and I say it's better to just go based on trials. It might work, but it probably won't...
Well my equation is based on the trials and has so far proved to be very reliable.
Yeah same. I haven't tried to predict the final temperature solely based on trials. It doesn't account for room temperature changes.
Re: Thermodynamics B/C Build
Posted: February 5th, 2019, 6:01 pm
by TheChiScientist
CaTaStRoPhY wrote:CPScienceDude wrote:CookiePie1 wrote:
I still don't believe in equations and I say it's better to just go based on trials. It might work, but it probably won't...
Well my equation is based on the trials and has so far proved to be very reliable.
Yeah same. I haven't tried to predict the final temperature solely based on trials. It doesn't account for room temperature changes.
Note that room temperature changes are normally irrelevant to the degree that unless your room in 100F or 0F you have no need to worry.
Re: Thermodynamics B/C Build
Posted: February 5th, 2019, 6:09 pm
by UTF-8 U+6211 U+662F
TheChiScientist wrote:CaTaStRoPhY wrote:CPScienceDude wrote:
Well my equation is based on the trials and has so far proved to be very reliable.
Yeah same. I haven't tried to predict the final temperature solely based on trials. It doesn't account for room temperature changes.
Note that room temperature changes are normally irrelevant to the degree that unless your room in 100F or 0F you have no need to worry.
Confirming, I adjusted room temp from around 22-26 degrees Celsius and it had no measurable effect as far as I could tell
Re: Thermodynamics B/C Build
Posted: February 5th, 2019, 6:10 pm
by olhs4n6
ElPotato wrote:CookiePie1 wrote:TheChiScientist wrote:
Well to a degree. You have heat loss and then that heat loss increases to a point when water is transferred multiple times. So it can depend on the situation.
I still don't believe in equations and I say it's better to just go based on trials. It might work, but it probably won't...
I agree, I've always used trials. Equations assume that your box is pretty ideal, and imo they don't take into account all the random discrepancies that can occur during competition.
I have also used trials both years I've been in the event, and I've never been more than a degree or two at most. They're more reliable especially when you can account for timing difficulties. At our state tournament the event supervisors didn't start timing until we made our predictions, but they wouldn't let us predict until 2 minutes had already passed. I feel like the trials would definitely work better in weird cases like this, but to be fair, I've never tried an equation.
2 simple auestions need answers
Posted: February 7th, 2019, 4:53 pm
by geniusjohn5
1. Can we put the cotton swab in the hole of our device DURING the actual cooling down process? 2. How many graphs do we need?
Re: 2 simple auestions need answers
Posted: February 7th, 2019, 5:05 pm
by olhs4n6
geniusjohn5 wrote:1. Can we put the cotton swab in the hole of our device DURING the actual cooling down process? 2. How many graphs do we need?
1. In the competitions I've been in, you put a cotton
ball inside the hole of the device during the entirety of the cooling process.
2. The rules say: 2 points for including data spanning at least one variable range, 2 points for including at least 10 data points in each data series, 2 points for proper labeling (e.g. title, team name, units) and
0.5 points for each graph or table turned in (up to 2 points total as long as they are not the same) (so 4 total graphs)
Re: Thermodynamics B/C Build
Posted: February 7th, 2019, 6:37 pm
by geniusjohn5
What are the standard units for using the Newton's Law of cooling? Especially for the K value? Should it be in seconds, hours, minutes?
Re: Thermodynamics B/C Build
Posted: February 7th, 2019, 6:42 pm
by UTF-8 U+6211 U+662F
geniusjohn5 wrote:What are the standard units for using the Newton's Law of cooling? Especially for the K value? Should it be in seconds, hours, minutes?
Probably seconds, but you can switch to whatever's convenient
Re: 2 simple auestions need answers
Posted: February 8th, 2019, 11:29 am
by C8H10N4O2!
olhs4n6 wrote:geniusjohn5 wrote:1. Can we put the cotton swab in the hole of our device DURING the actual cooling down process? 2. How many graphs do we need?
1. In the competitions I've been in, you put a cotton
ball inside the hole of the device during the entirety of the cooling process.
2. The rules say: 2 points for including data spanning at least one variable range, 2 points for including at least 10 data points in each data series, 2 points for proper labeling (e.g. title, team name, units) and
0.5 points for each graph or table turned in (up to 2 points total as long as they are not the same) (so 4 total graphs)
You just need 4 data sets, so basically 4 trials. I combined them all into a graph, but that is not required. The rules say graphs/charts (or something similar to that, but you can have charts)