A pot with a steel bottom 1.2 cm thick rests on a hot stove. The area of the bottom of the pot is 0.150 sq. m. The water inside the pot is at 100°C and 0.440 kg vaporize in every 5 minutes. The temperature of the lower surface of the pot, which is in contact with the stove is (Given: Lv = 2.256 × 10^6 J/kg and Ksteel = 50.2 W/m - K)