DENDROLOGY

Detailed explanation-1: -Why does this happen? The sinking and floating are depended on the surface area. The wooden boats or the iron ship is hollow and the empty space contains which makes the average density. So they float on water.

Detailed explanation-2: -If the downward gravitational force is less than the upward buoyancy force then the object floats, otherwise it sinks. That is, if an object weighs less than the amount of water it displaces then it floats otherwise it sinks. A boat floats because it displaces water that weighs more than its own weight.

Detailed explanation-3: -Wooden boats were made water-resistant by putting tar in the hull of the boat. The pitch or tar sealed the wooden boards of the ship together, keeping water out and allowing the boat to float. Sailors also utilized oil on their sails in another form of waterproofing.