Keep the Heat B/Thermodynamics C

[hmcginny]

Well the rate of heat change depends on the exposed surface area A (R=kA(T1-T2)/d), so since each dimension is doubled, the surface area will be quadrupled. Therefore the rate of heat added to the house would have to be quadrupled as well to make up for the quadrupled heat loss. I hope that makes sense.

[questionguy]

Well the rate of heat change depends on the exposed surface area A (R=kA(T1-T2)/d), so since each dimension is doubled, the surface area will be quadrupled. Therefore the rate of heat added to the house would have to be quadrupled as well to make up for the quadrupled heat loss. I hope that makes sense.

Yes, it does thank you very much

[andrewwski]

Drawings of two designs we have. One is a box within a box. The other one is...something, I guess...
Excuse my terrible handwriting; I drew this on a laptop.
Box inside a box
The other design with a lot of layers
Yeah, if you guys don't understand the diagrams at all, ask.

You might want to rethink your design, because while water may be an adequate insulator it absorbs ALOT of heat, so unless you plan on using hot water(which I'm pretty sure is not aloud) then the water will be room temperature and almost certainly cool down the beaker even more than if you just had air

Absolutely. But absorbing heat means water isn't an adequate insulator. Water has a thermal conductivity of about 0.6 W/mK, and air has a thermal conductivity of about 0.025 W/mK. Fourier's Law states that , where k is conduction and is the temperature gradient (or change in temperature with respect to distance. So heat lost is directly proportional to the thermal conductivity of the conducting material.

By using water instead of air, you'll lose heat at over 20 times the rate you would by using air. (A perfect calculation is more difficult in this case, as it's not a true steady-state problem, but it's on the right order).

[Flavorflav]

Which is why it is so useful for quenching, to which I alluded earlier. Of course, that makes it worse than useless in this event.

[foreverphysics]

Yeah, that's why there's styrofoam first. (Yes, I'll think of something other than styrofoam eventually, but for right now, let's just stick with a generic name "styrofoam".) If I put cardboard coated in aluminum foil as opposed to plastic, it should actually work pretty well.

[Frogger4907]

Yeah, that's why there's styrofoam first. (Yes, I'll think of something other than styrofoam eventually, but for right now, let's just stick with a generic name "styrofoam".) If I put cardboard coated in aluminum foil as opposed to plastic, it should actually work pretty well.

What do you guys find to be the benefits of using the Al foil?

[PacificGoldenPlover]

Yeah, that's why there's styrofoam first. (Yes, I'll think of something other than styrofoam eventually, but for right now, let's just stick with a generic name "styrofoam".) If I put cardboard coated in aluminum foil as opposed to plastic, it should actually work pretty well.

But there is no styrofoam allowed!!!
I think the closest you could come is some sort of natural fiber.

[harryk]

Yeah, that's why there's styrofoam first.

Maybe you didn't quite get it the first time
If you have water anywhere in your box(other than the beaker) it WILL HURT YOUR SCORE

[val_chen_11]

I'm new to this and I was wondering, for those of you experienced people, if you can give me some advice on the what the graphs are supposed to display....Is it supposed to start from the beginning to the end of the 40 min or is it supposed to show form 20-40 min....or any other advice. thanks

[JSGandora]

Mine was always 20-40 minutes and it's always gotten full credit.