The inner surface of a cold-storage wall is at while the outer surface is at

PHYSICS · Multi-part · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics

Problem

The inner surface of a cold-storage wall is at

30^{\circ}\text{C}

while the outer surface is at

0^{\circ}\text{C}

. The wall is made of two layers in contact: wood of thickness

1.0\,\text{cm}

(

k = 0.15\,\text{W m}^{-1}\text{K}^{-1}

) and glass wool of thickness

3.0\,\text{cm}

(

k = 0.04\,\text{W m}^{-1}\text{K}^{-1}

). The cross-sectional area is

0.50\,\text{m}^2

. (i) Calculate the steady heat current through the wall. (ii) Determine the temperature at the interface between the wood and the glass wool layers.