posted by john on .
Icebergs in the North Atlantic present hazards to shipping, causing the length of shipping routes to increase by about 30 percent during the iceberg season. Attempts to destroy icebergs include planting explosives, bombing, torpedoing, shelling, ramming, and painting with lampblack. Suppose that direct melting of the iceberg, by placing heat sources in the ice, is tried. How much heat is required to melt 14 percent of a 2.40×105 metric-ton iceberg? One metric ton is equal to 103 kg. Assume that the iceberg is at 0°C. (Note: To appreciate the magnitude of this energy, compare your answer to the Hiroshima atomic bomb which had an energy equivalent to about 15,000 tons of TNT, representing an energy of about 6.0×1013 J.)
Convert 2.40 x 10^5 metric tons to grams. Then heat required is
q = mass x heat fusion
You have the mass, look up the heat of fusion of ice and do the calculation.
You can multiply your answer by 0.14 to obtain the energy required to melt just 14% of the iceberg.