Occasionally, huge icebergs are found floating on the ocean's currents. Suppose one such iceberg is 128 km long, 38.7 km wide, and 215 m thick. (a) How much heat in joules would be required to melt this iceberg (assumed to be at 0 °C) into liquid water at 0 °C? The density of ice is 917 kg/m3. (b) The annual energy consumption by the United States in 1994 was 9.3 x 1019 J. If this energy were delivered to the iceberg every year, how many years would it take before the ice melted?