Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: Do you see the man sitting on top of this tanker truck? He gives you a sense of how big the truck is. What's behind the truck? Is it a huge apartment complex? It's just as massive as a very large building, but it's not even resting on land. It's a giant cruise ship, and it's floating on water. The ship weighs about 100,000 metric tons. How can such a tremendous weight float on water? Why doesn't it sink to the bottom of the ocean instead? Archimedes' law explains why. Answer: archimedes' law
Which law explains why a ship weighing thousands of metric tons floats on water?