Water at 80 °c is pumped through 100 m of stainless steel pipe, k = 16 w/m k of inner and outer radii 47 mm and 50 mm respectively. the heat transfer coefficient due to water is 2000 w/m² k. the outer surface of the pipe at 20 °c loses heat by convection with a heat transfer coefficient is 200 w/m². k. a- calculate the heat flow through the pipe. b- now, suppose that we want to reduce the rate of heat loss from the pipe to the air to only 5.39 kw by adding a layer of insulation with k= 0.1 w/m k, calculate the required thickness of the insulation.