Physics

Problem

A cold-storage room is separated from the outside atmosphere by a flat wall of area

8\,\text{m}^2

. Starting from the interior side, the wall consists of a

5\,\text{cm}

thick layer of polyurethane foam (

k = 0.03\,\text{W m}^{-1}\,\text{K}^{-1}

) firmly bonded to a

10\,\text{cm}

thick brick layer (

k = 0.60\,\text{W m}^{-1}\,\text{K}^{-1}

). The room air is maintained at

-5^{\circ}\text{C}

while the outside air is at

35^{\circ}\text{C}

. Steady one-dimensional heat flow may be assumed. a. (i) Calculate the rate of heat flow through the composite wall. b. (ii) Determine the temperature at the interface between the foam and the brick.

Browse the problem library