Copperpipe with a length of 2 meters, 0.0004 meters thick and a surface area of 0.12 m^{2}, is used to heat a room via hot water running through the pipe. The water running through is 80 oC. Now we assume that the room temperature outside the pipe is a constant 15 oC . The thermal conductivity in the copper is 400 \frac{W}{m\cdot K}
The question: Calculate the heat flux from the water through the copperpipe.
Is the assumption about the room temperature being 15 oC reasonable?