Chapter 18, Problem 60P

GO Figure 18-46 shows the cross section of a wall made of three layers. The layer thicknesses are L₁, L₂ = 0.700L₁, and L₃ = 0.350L₁. The thermal conductivities are k₁, k₂ = 0.900 k₁, and k₃ = 0.800 k₁. The temperatures at the left side and right side of the wall are T_H = 30.0°C and T_C = −15.0°C, respectively. Thermal conduction is steady. (a) What is the temperature difference ΔT₂ across layer 2 (between the left and right sides of the layer)? If k₂ were, instead, equal to 1.1k₁, (b) would the rate at which energy is conducted through the wall be greater than, less than, or the same as previously, and (c) what would be the value of ΔT₂?

Figure 18-56 Problem 60.