Buoyancy question. Why does a steel nail sinks but a steel ship floats.?
A steel nail is much denser than the water. That means that it weighs more than an equivalent volume of water. Therefore, the buoyancy is never going to be enough to hold it up. Whether it is a big steel nail or a small one, it will always be too dense for the water to support it. Because of its shape, a steel ship is not as dense as water. It is not made out of a solid block of steel. Instead, the hull is built of thin plates of steel enclosing an open space. A steel ship is sort of like an empty cup. Although its sides are hard and dense, it holds a lot of air in the middle. Since air weighs almost nothing, it lowers the overall density of the ship to a point where its buoyancy exceeds its weight, and the ship floats. Think of it as you trying to sink a balloon.
