A stainless-steal sphere has inner & outer radii of 20 and 27 mm, respectively. The sphere contains hot liquid at temperature of 80 C, and the surrounding air temperature is 20 C. What is the rate of heat flow via conduction and convection of this sphere? Suppose that the heat transfer coefficient of air side and liquid side are 15 W/m K and 40 k W/m K, respectively, and the thermal conductivity of the sphere is 19 W/m. K.