I have been rather unfortunate to attend a school with a physics department that uses Sears and Zemansky's University Physics textbook. I have been working unsuccessfully on the following problem (Chapter 15, #103 for those who have the book) for 2 days...(adsbygoogle = window.adsbygoogle || []).push({});

Show that the thickness of the ice sheet formed on the surface of a lake is proportional to the square root of the time if the heat of fusion of the water freezing on the underside of the ice sheet is conducted through the ice sheet

Here is what I know... or think I know...

heat current = dQ/dt = (kA(Th - Tc))/L

That is the only equation I have that involves time; however I was always under the impression that I cannot seperate dQ/dt since dt is part of an expression representing the instantaneous heat flow, and not a single variable.

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# Homework Help: Time Needed for a Lake to Freeze Over

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