Steam at 320 c flows in a cast iron pipe (k = 80 w/mk) whose inner and outer diameters are 5 cm and 5.5 cm respectively. the pipe is covered with 3 cm thick glass wool insulation with k = .05 w/m-k. heat is lost to the surrounding at 5 c by natural convection with heat transfer coefficient of 60 w/m^2-k. taking the heat transfer coefficient inside the pipe to be 18 w/m^2k, determine the rate of heat loss from the steam per unit length of the pipe. also determine the temperature drop across the pipe shell and the insulation.