3. You have the task of determining how thick a sheet of aluminum oxide must be to provide enough thermal resistance to allow a maximum heat flux of 56,000 W/m?

to pass through between a hot kettle for melting a metal (where the inside surface of the aluminum oxide sheet is at 427 °C) and the surrounding laboratory (where the sheet's surface is 32 °C). You may assume 1-D (Cartesian), steady state heat transfer, but not constant k. A. What thickness is needed? (convert your answer to inches) B. Discuss whether you think your answer is reasonable (that is, is the answer far too big or too small, or about right for providing the insulation needed. C. What is the temperature at the midplane of the aluminum oxide sheet (the midpoint of the thickness)?