A solid wood door has dimensions; height = 2m, width = 0.8m, thickness = 0.04m. Its thermal conductivity is K=0.04 Js−1m1(∘C)−1. The inside air temperature is 20∘C and outside air temperature is −10∘C. What is the rate of heat flow through the door, assuming the surface temperatures are those of the surrounding air.
The correct option is B 48 watts