Calculate the critical radius of insulation for asbestos (x= 0.172 W/m K) surrounding a pipe and exposed to a room air at 300K with h = 2.8 W/mr K. Calculate the heat loss from a 475 K, 60 mm diameter pipe when covered with the critical radius of insulation and without insulation. (110.2 W/m, 92.4 W/m)