Consider a water pipe of length L=17m, inner radius r1=15cm, outer radius r2=20cm, and thermal conductivity k=14W/m*k. Heat is generated in the pipe material uniformly by a 25-kW electric resistance heater. The inner and outer surfaces of the pipe are at T1=60C and T2=80C, respectively. Obtain a general relation for temperature distribution inside the pipe under steady conditions and determine the temperature at the center plane of the pipe.