Thermodynamics B/C

[Bobbycat]

Ice Water Bonus (IWB) = (volume of ice water in ml /10) points
Teams may elect to add up to 50 mL of water from an ice bath to their internal beaker immediately after
receiving the hot water for bonus points. Each team may choose their own volume.

Do any of you know how to effectively use ice water in this event to your advantage? Is 5 points extra really worth the ice water, along with more careful predictions of the final insulator beaker? Or is it useless?

Those 5 points could help if you can predict it right.I don't really know but 10 points made the difference of like 10 rankings at an invitational so the 5 points could give you an upper edge.

However since the ice water is only in the internal breaker doesn't reduce your HRF?

Since this has the possibility of being 15 points if you have a high HRF I think the ice could be a draw back.

[John Richardsim]

Ice Water Bonus (IWB) = (volume of ice water in ml /10) points
Teams may elect to add up to 50 mL of water from an ice bath to their internal beaker immediately after
receiving the hot water for bonus points. Each team may choose their own volume.

Do any of you know how to effectively use ice water in this event to your advantage? Is 5 points extra really worth the ice water, along with more careful predictions of the final insulator beaker? Or is it useless?

Those 5 points could help if you can predict it right.I don't really know but 10 points made the difference of like 10 rankings at an invitational so the 5 points could give you an upper edge.

However since the ice water is only in the internal breaker doesn't reduce your HRF?

Since this has the possibility of being 15 points if you have a high HRF I think the ice could be a draw back.

It would reduce HRF, but that being said the difficulty is trying to determine the extent to which it would reduce the HRF score. So Long as the IWB score is greater than your loss of HRF score, it is a gain for your final score.

That being said, since the HRF score is set such that the team with the best HRF gets all 15 points, I think in order to accurately use it you'd need to have a pretty good guess at the best HRF at the competition. This introduces a bit of uncertainty, and thus risk. In addition, I'm sure prediction of the internal beaker temperature would also be more difficult, so you're also messing with that score as well.

Overall I can't imagine that the IWB ends up really being that much of a bonus. I looked at the raw scores from 2013 nationals to see which teams went for IWB. Generally, most teams that did IWB were in the top 20 or 30. However, I'm assuming these teams did well because they had spent enough time with their devices to feel confident in going for it, not that actually going for it had that much of an effect. Most teams (including the first place team) did not use IWB.

[Ashernoel]

Those 5 points could help if you can predict it right.I don't really know but 10 points made the difference of like 10 rankings at an invitational so the 5 points could give you an upper edge.

However since the ice water is only in the internal breaker doesn't reduce your HRF?

Since this has the possibility of being 15 points if you have a high HRF I think the ice could be a draw back.

It would reduce HRF, but that being said the difficulty is trying to determine the extent to which it would reduce the HRF score. So Long as the IWB score is greater than your loss of HRF score, it is a gain for your final score.

That being said, since the HRF score is set such that the team with the best HRF gets all 15 points, I think in order to accurately use it you'd need to have a pretty good guess at the best HRF at the competition. This introduces a bit of uncertainty, and thus risk. In addition, I'm sure prediction of the internal beaker temperature would also be more difficult, so you're also messing with that score as well.

Overall I can't imagine that the IWB ends up really being that much of a bonus. I looked at the raw scores from 2013 nationals to see which teams went for IWB. Generally, most teams that did IWB were in the top 20 or 30. However, I'm assuming these teams did well because they had spent enough time with their devices to feel confident in going for it, not that actually going for it had that much of an effect. Most teams (including the first place team) did not use IWB.

Also, if your device has the greatest HRF without the bonus, going for IWB would increase other teams' scores as well as lower your HRF by similar amount of points.

I think some scenarios exist where the bonus from 50 ml would not effect Heat retention score more than 4 points, but then we are talking about <1 point and in the minority of cases. ]

Though, I have heard that IWB will let a team adjust volume to a desired level, perhaps reducing heat lost through convection due to less air. This volume consistency and reduced heat loss, combined with the smaller temp differential because of the lower starting temp, has the potential to help to increase the prediction score if done well.

[Billbillsmiths]

Can I tell you something? (Click to Show Hidden Text)

[img]https://media.giphy.com/media/PzV2oB0r8GvtK/giphy.gif[/img]

That’s what I thought too but “can make a great device from it” seemed legit. Anyway, I seriously am surprised by the MSDS, because nearly all aerogel blankets have fiberglass or rock wool, but I couldn’t find it on that one.

Spam hints:
1. It's their only post.
2. Capitalization, punctuation, and grammar are incorrect.
3. It includes a link.

Trying to help here only. don’t have any relationship to buyareogel.com whatsoever! No point to spam.
I’m not on that event.all I can tell u if do it right, performance is way better than vacuum cup .

[arv101]

With all this discussion of fiberglass in the blankets, how exactly can the es tell? Isn't fiberglass like pink? (I am a noob at this kind of stuff)

[JoeyC]

With all this discussion of fiberglass in the blankets, how exactly can the es tell? Isn't fiberglass like pink? (I am a noob at this kind of stuff)

In response to your question, in the MDS (material data sheet) it will say if or if it doesn't have fiberglass on it. This is a mandated practice, and any legitimate seller should have the MDS within easy access; some websites will have it right next to the product, and products will have it on their packaging. Don't worry; the MDS isn't like a Terms of Usage contract, you should find it pretty easy to read. But most, if not all aerogel blankets have fiberglass , and HREF (heat retention factor) isn't really worth that much; the test is much more important

[JoeyC]

However since the ice water is only in the internal breaker doesn't reduce your HRF?

Since this has the possibility of being 15 points if you have a high HRF I think the ice could be a draw back.

It would reduce HRF, but that being said the difficulty is trying to determine the extent to which it would reduce the HRF score. So Long as the IWB score is greater than your loss of HRF score, it is a gain for your final score.

That being said, since the HRF score is set such that the team with the best HRF gets all 15 points, I think in order to accurately use it you'd need to have a pretty good guess at the best HRF at the competition. This introduces a bit of uncertainty, and thus risk. In addition, I'm sure prediction of the internal beaker temperature would also be more difficult, so you're also messing with that score as well.

Overall I can't imagine that the IWB ends up really being that much of a bonus. I looked at the raw scores from 2013 nationals to see which teams went for IWB. Generally, most teams that did IWB were in the top 20 or 30. However, I'm assuming these teams did well because they had spent enough time with their devices to feel confident in going for it, not that actually going for it had that much of an effect. Most teams (including the first place team) did not use IWB.

Also, if your device has the greatest HRF without the bonus, going for IWB would increase other teams' scores as well as lower your HRF by similar amount of points.

I think some scenarios exist where the bonus from 50 ml would not effect Heat retention score more than 4 points, but then we are talking about <1 point and in the minority of cases. ]

Though, I have heard that IWB will let a team adjust volume to a desired level, perhaps reducing heat lost through convection due to less air. This volume consistency and reduced heat loss, combined with the smaller temp differential because of the lower starting temp, has the potential to help to increase the prediction score if done well.

If I am correct, (which lol, I am not with any reasonable amount of consistency when hypothesizing) if you have low initial temperatures, then ice water bonus won't be as harmful to your HREF score comparatively to if you used IWB at high temperatures. Similarly, the less water you have, the more harmful IWB will be relative to having a lot of water.
So my theory is this:

IWB is Harmful | IWB is Beneficial
-----------------------------------------------------------------------
Low Initial Temperature | High Initial Temperature
Low Volume of Water | High Volume of Water


Please correct me if I'm wrong !!!

[Justin72835]

If I am correct, (which lol, I am not with any reasonable amount of consistency when hypothesizing) if you have low initial temperatures, then ice water bonus won't be as harmful to your HREF score comparatively to if you used IWB at high temperatures. Similarly, the less water you have, the more harmful IWB will be relative to having a lot of water.
So my theory is this:

IWB is Harmful | IWB is Beneficial
-----------------------------------------------------------------------
Low Initial Temperature | High Initial Temperature
Low Volume of Water | High Volume of Water


Please correct me if I'm wrong !!!

I'm pretty sure you're right about this. However, although it may not be "as harmful", I would be hesitant to say that it would be beneficial. With that said, it is worth much more trouble than it is actually worth. The time spent testing for the IWB could easily be spent doing more testing or studying.

Because of this, I foresee that IWB either being completely removed or worth significantly more for the 2018-2019 season.

[Gr8tor]

I agree completely. The IWB isn't worth enough to be useful this year. They should have made it worth more. It makes it harder to predict as well. I've tried.

[JoeyC]

Alright, now that I've studied enough to competent, what type of thermo question is the hardest (assuming you have appropriate notes and a decent knowledge of AP Physics II covering fluid dynamics and thermodynamics). I believe it could be the calculation problems, but as long as you understand what to use in your equations and keep a close, close, close eye on those units, you'll usually be fine. Meanwhile history can be hard because history is big, and even though you have infinite notes (unless you find a way to fill up a 3 ring binder ) it can be hard to find those specific facts. What do you guys think? Is one specific type of question harder, or are they of equal difficulty if you came prepared?