Thermodynamics B/C

[Justin72835]

Does anybody know if using a smaller box will help with heat insulation? My intuition tells me that if you have a smaller surface area then that would equate to less heat being transferred between the beaker and the outside of the box, but I just wanted to make sure with others first.

[robloxparodies]

Do we need to explain the components of the device and bring in a picture of it prior to competition?

[UTF-8 U+6211 U+662F]

Do we need to explain the components of the device and bring in a picture of it prior to competition?

Not sure about explaining the components, but diagrams and graphs are generally impounded before the first event time slot of a competition.

[TheChiScientist]

Does anybody know if using a smaller box will help with heat insulation? My intuition tells me that if you have a smaller surface area then that would equate to less heat being transferred between the beaker and the outside of the box, but I just wanted to make sure with others first.

No, not at all.This is mainly due to conduction that this would cause you a problem.To simplify it without going in to deep into the science of it More matter=More heat retention as you are slowing down the heat loss via conduction which is one of the main sources of heat loss.

[UTF-8 U+6211 U+662F]

Does anybody know if using a smaller box will help with heat insulation? My intuition tells me that if you have a smaller surface area then that would equate to less heat being transferred between the beaker and the outside of the box, but I just wanted to make sure with others first.

No, not at all.This is mainly due to conduction that this would cause you a problem.To simplify it without going in to deep into the science of it More matter=More heat retention as you are slowing down the heat loss via conduction which is one of the main sources of heat loss.

Looking at the thermal conductivity equation, there are two things that matter, the surface area and the thickness. It would then seem that you have to balance the surface area exposed with the thickness, meaning that more thickness does not necessarily imply more heat retention (e.g. if you double the thickness of the material but quadruple the surface area, then that might actually decrease heat retention).

EDIT: Given that the beaker is approximately a rectangular prism with 7 cm x 7 cm x 9 cm, then



.

Make of that what you will.

[robloxparodies]

Do we need to explain the components of the device and bring in a picture of it prior to competition?

Not sure about explaining the components, but diagrams and graphs are generally impounded before the first event time slot of a competition.

A diagram of the device?

[UTF-8 U+6211 U+662F]

Do we need to explain the components of the device and bring in a picture of it prior to competition?

Not sure about explaining the components, but diagrams and graphs are generally impounded before the first event time slot of a competition.

A diagram of the device?

Yes, as stated in the rules.

[JoeyC]

Does anybody know if using a smaller box will help with heat insulation? My intuition tells me that if you have a smaller surface area then that would equate to less heat being transferred between the beaker and the outside of the box, but I just wanted to make sure with others first.

No, not at all.This is mainly due to conduction that this would cause you a problem.To simplify it without going in to deep into the science of it More matter=More heat retention as you are slowing down the heat loss via conduction which is one of the main sources of heat loss.

Looking at the thermal conductivity equation, there are two things that matter, the surface area and the thickness. It would then seem that you have to balance the surface area exposed with the thickness, meaning that more thickness does not necessarily imply more heat retention (e.g. if you double the thickness of the material but quadruple the surface area, then that might actually decrease heat retention).

EDIT: Given that the beaker is approximately a rectangular prism with 7 cm x 7 cm x 9 cm, then



.

Make of that what you will.

Therefore, the solution that I have used in my past competition is, using intuition, making the box as big as possible, and then minimizing the interior surface area by filling it in with more material.
If you don't get what I'm saying, please forgive my horrible phrasing, basically I made our device a 20 by 20 by 20 cube of styrofoam, and next filled the box with styrofoam until the walls surrounding the beaker were smaller. This allowed high thickness, giving better heat retention, and also allowed for small surface area. (as it is only the interior surface are that matters)

[JoeyC]

If you wish to picture it a different way, basically imagine the smallest possible box that could hold a beaker and follow the rules.
Now keep adding layers around that box til it is a 20 by 20 by 20 cube (for B division).
Now you have higher thickness and the same interior surface area (which, if you look at the equation, is the one we use in calculations) as the small box we started out with.

[TheChiScientist]

Either way, you are better off layering your box and then figure out a way to stop immediate heat loss.