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### Re: Thermodynamics B/C

Posted: April 8th, 2018, 3:41 pm
Alex-RCHS wrote:
UTF-8 U+6211 U+662F wrote:
Alex-RCHS wrote: You can find the function of the line going right through those points. The function would be final temperature as a function of starting temperature, and it would be as simple as y = mx + b. Then plug in 63.
This isn't the greatest idea, since it's very doubtful the data will form a line. The only way to know what the data is going to turn out like is to test it (which is painful, I know)
Lol, it’ll be close enough. The relationship may not be exactly linear but it will be very, very close to it. You might be off an extra 0.2 degrees or something but it’s worth the time saved. Spend that extra time studying instead.

Also, there are other functions you can make which would model the data more closely, but that’s up to you.
On the same topic, usually, the temperature drops rapidly for around the first five minutes, then begins to settle into the regression curve. How is it possible to calculate this initial drop regardless of your initial temperature?

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 4:31 pm
Justin72835 wrote:
Alex-RCHS wrote:
UTF-8 U+6211 U+662F wrote: This isn't the greatest idea, since it's very doubtful the data will form a line. The only way to know what the data is going to turn out like is to test it (which is painful, I know)
Lol, it’ll be close enough. The relationship may not be exactly linear but it will be very, very close to it. You might be off an extra 0.2 degrees or something but it’s worth the time saved. Spend that extra time studying instead.

Also, there are other functions you can make which would model the data more closely, but that’s up to you.
On the same topic, usually, the temperature drops rapidly for around the first five minutes, then begins to settle into the regression curve. How is it possible to calculate this initial drop regardless of your initial temperature?
That initial drop is partially due to the heat entering the beaker (which also depends on what material you use for the beaker). I’m not sure why you would need to calculate it though.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 5:35 pm
Wait a minute! I keep hearing all this talk of different beakers.Are you, people implying that the rules allow different material beakers? If so what type of beakers are you people using? I am using Pyrex Beakers.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 5:51 pm
TheChiScientist wrote:Wait a minute! I keep hearing all this talk of different beakers.Are you, people implying that the rules allow different material beakers? If so what type of beakers are you people using? I am using Pyrex Beakers.
same. I dont think it makes much difference.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 5:52 pm
But if it does I wanna know.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 5:58 pm
Your beakers have to be plastic or glass and they have to be identical. It does make a difference what material you use, at least for the heat retention, but I wouldn’t get caught up in it at this point in the season. Ultimately, you want a material that won’t absorb much heat from the water poured into it and will do so at a low rate — I’ll let you all figure out the rest.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 6:27 pm
The key is that there's also a control beaker outside though?

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 6:27 pm
Yes I believe so as well

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 6:33 pm
UTF-8 U+6211 U+662F wrote:The key is that there's also a control beaker outside though?
True, but I think the control beaker will cool down so much that the difference in beaker materias won’t effect the control beaker as much as the internal beaker. But you’re right, it should offset it some.

### Re: Thermodynamics B/C

Posted: April 8th, 2018, 7:02 pm
TheChiScientist wrote:Wait a minute! I keep hearing all this talk of different beakers.Are you, people implying that the rules allow different material beakers? If so what type of beakers are you people using? I am using Pyrex Beakers.
Since plastic beakers are allowed, they insulate better, but it shouldn't affect your HRF. I prefer pyrex beakers but there is no real scientific reason behind it.