00:01
So we have a styrofoam icebox with an area of 0 .95 square meters.
00:06
And it's trying to maintain a temperature difference of 36 degrees celsius.
00:12
The outside temperature is 36.
00:14
The inside temperature is presumably 0 celsius.
00:17
It has a thickness of 0 .025 meters or 2 .5 centimeters.
00:24
And the styrofoam has a thermal conductivity, we'll call this kappa, of 0 .01 watts per meter per degree celsius.
00:33
And we want to know over the course of one hour how much heat is transferred to the styrofoam box.
00:41
So the heat flux, let's just call this cube, is like the heat or the power per square meter of heat energy transfer.
00:50
And this is going to be kappa times our temperature difference over l.
00:55
And so if you plug in our numbers, we get 0 .01 watts per meter per degree celsius times 36 degrees celsius divided by 0 .025 meters...