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Re: Thermodynamics B/C

Posted: November 3rd, 2018, 6:06 pm
by bryan,boyd
Hey quick question, since in AP Physics 2 the convention for work they use is that work done by the surroundings on the system is positive. I was curious if for science olympiad, is that convention the same or is it the opposite and that work doe by the system on the surroundings would be considered positive. Thanks.

Re: Thermodynamics B/C

Posted: November 3rd, 2018, 6:40 pm
by UTF-8 U+6211 U+662F
bryan,boyd wrote:Hey quick question, since in AP Physics 2 the convention for work they use is that work done by the surroundings on the system is positive. I was curious if for science olympiad, is that convention the same or is it the opposite and that work doe by the system on the surroundings would be considered positive. Thanks.
I would guess the convention would be the same, but since it's just a convention, it shouldn't have any impact on the final answer (unless the question is vaguely worded).

Re: Thermodynamics B/C

Posted: November 19th, 2018, 11:38 am
by Killboe
Anybody have any tips on what to study for this event

Re: Thermodynamics B/C

Posted: November 19th, 2018, 12:28 pm
by BasuSiddha23
Killboe wrote:Anybody have any tips on what to study for this event
I did this event last year and I found that the hyperphysics thermodynamics website has great resources. To understand the concepts better, I would suggest watching Khan Academy videos on thermodynamics. For the history part of the test, I would find timelines for the accomplishments of thermodynamics. I used Wikipedia in all parts of the test and it was pretty useful.

Re: Thermodynamics B/C

Posted: November 21st, 2018, 8:46 am
by takuramen89
Hey guys,
This is going to be my second year doing Thermodynamics. Last year I worked on the build and notes and was never able to do a lot of the actual test and basically got carried. This year I really want to do well on the test as well. I really don't know where to start studying from, and I'm pretty familiar with a lot of the things on the scioly wiki already. Does anyone have any good resources for studying and what topics of thermodynamics should i start studying from? Thanks.

Re: Thermodynamics B/C

Posted: November 21st, 2018, 10:31 am
by UTF-8 U+6211 U+662F
takuramen89 wrote:Hey guys,
This is going to be my second year doing Thermodynamics. Last year I worked on the build and notes and was never able to do a lot of the actual test and basically got carried. This year I really want to do well on the test as well. I really don't know where to start studying from, and I'm pretty familiar with a lot of the things on the scioly wiki already. Does anyone have any good resources for studying and what topics of thermodynamics should i start studying from? Thanks.
Check out websites like Khan Academy, HyperPhysics, etc. Look up any concepts you don't reecognize.

Re: Thermodynamics B/C

Posted: December 1st, 2018, 9:02 pm
by BenW
takuramen89 wrote:Hey guys,
This is going to be my second year doing Thermodynamics. Last year I worked on the build and notes and was never able to do a lot of the actual test and basically got carried. This year I really want to do well on the test as well. I really don't know where to start studying from, and I'm pretty familiar with a lot of the things on the scioly wiki already. Does anyone have any good resources for studying and what topics of thermodynamics should i start studying from? Thanks.
This is personally my first year, but I think that for the history of thermodynamics, the Wikipedia (general) page of a timeline of thermodynamics should help.

Re: Thermodynamics B/C

Posted: December 2nd, 2018, 5:39 pm
by CookiePie1
BenW wrote:
takuramen89 wrote:Hey guys,
This is going to be my second year doing Thermodynamics. Last year I worked on the build and notes and was never able to do a lot of the actual test and basically got carried. This year I really want to do well on the test as well. I really don't know where to start studying from, and I'm pretty familiar with a lot of the things on the scioly wiki already. Does anyone have any good resources for studying and what topics of thermodynamics should i start studying from? Thanks.
This is personally my first year, but I think that for the history of thermodynamics, the Wikipedia (general) page of a timeline of thermodynamics should help.
The problem with history is that it is sometimes very, very obscure, and I've found that the general wikipedia page is absolutely not enough. What you should do is go into as many practice tests as you can find, and write down all the history facts. What you should also do is go into the Wikipedia book about thermodynamics and take some notes on all the people listed in there. That should help a lot with history, but sometimes, if you really don't know an answer, you're probably not going to get it right in the history section.

Re: Thermodynamics B/C

Posted: December 7th, 2018, 7:47 am
by cwscio
I have question about the formula for scoring for "k". I don't see an explanation anywhere or an example. I have been fooling around with the spreadsheet and am not getting the same numbers as the spread sheet.

conditions: Div B so time is 25 min- Water at 75 degrees. Room at 74 deg F ( 23.3 deg C) Final temp 57.6 deg C

1/25 cooling time = .04
ln -using natural log function on my calculator on iphone

k = - (.04) * ln((75-23.3)/(57.6-23.3))


k = -(.04) * ln (51.7/34.3)


k = -(.04) * ln ( 1.507288)


k = -(.04) * ( 0.4103)


k =-0.016412


When I put these same values into the spreadsheet, it is giving me a k value of -0.9847.


Can a moderator or coach please explain?

Thanks

Re: Thermodynamics B/C

Posted: December 7th, 2018, 10:12 am
by EastStroudsburg13
From downloading the spreadsheet, it seems that it is measuring cooling time in hours. So it is using 0.417 hrs instead of 25 min:

1/0.417 = 2.4
k = -(2.4) * (0.4103)
k = -0.98472

Whether this is what the spreadsheet is supposed to be doing is a separate question that is beyond my familiarity.