A 5-m-internal-diameter spherical tank made of 1.5cm-thick stainless steel (k=15W/mK) is used to store iced water at 0C. The tank is located in a room whose temperature is 30C. The outer surface of the tank is black (emissivity, =1 ), and heat transfer between the outer surface of the tank and the surroundings is by convection and radiation. Heat transfer coefficients at the inner and the outer surfaces of the tank are 80W/m2K and 10W/m2K, respectively. Determine a) the rate of heat transfer to the iced water in the tank b) overall heat transfer coefficient