Final answer:
The buoyant force on a 20-ton ship floating in the ocean equals the weight of the ship, which is 20 tons, according to Archimedes' principle.
Step-by-step explanation:
The question asked is about the buoyant force acting on a 20-ton ship floating in the ocean. By Archimedes' principle, the buoyant force on an object is equal to the weight of the fluid that the object displaces. For a ship floating in the ocean, this means that the buoyant force must equal the weight of the ship. If the ship weighs 20 tons, then the buoyant force acting on it will also be 20 tons. This is because the ship is floating, which indicates that it's displacing a volume of water equal to its own weight. In addition, the information given states that the maximum buoyant force is ten times the weight of the steel used to build the ship, allowing it to carry a load nine times its own weight without sinking.