(a) Briefly describe the basic mechanism of convection heat transfer. [3 marks] (b) A steel pipe has an outer diameter of 0.06 m. It is covered with a 0.05 m thick layer of magnesia (k = 0.07 W m K) which in turn is covered with a 0.04 m layer of fibreglass insulation (k = 0.048 W m K). The pipe wall outside temperature is 380 K, and the outside surface temperature of the fibreglass is 310 K. What is the interfacial temperature between the magnesia and the Q 2rk (T, -T,), In(r, /r,) fibreglass? [For a single wall tube, [17 marks] %3D