This has been done before and done better, so I'm just putting up a slide show.
I needed a cheap way to keep food cold since I have a five hour break between my morning and afternoon class. Didn't want a nice cooler as that would just invite theft. So "Super Cooler" was born. The last slide is the Newton's Law of Cooling graph computed for the cooler before and after, k was computed by measuring change in temp over time and rearranging T=Tr+(Tn-Tr)e(-kx).
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