Why is a boat able to float

Why is a boat able to float. To explain the problem, we can do a test: put a piece of sheet iron in water, it immediately sank; If this piece of iron to make a box, the weight have not changed, it can float on the water; Not only that, put a few things in the box, box just sink, that still can float on the surface of the water. This is because the box on the underside of subject to the water pressure, the pressure is the vertical upward buoyancy, as long as the buoyancy is greater than the weight of the iron sheet, will hold the tin box to make it not under heavy. It's simply explained: why is a boat able to float. However, tin can float, so steel?

The modern big ships are the result of the steel, steel is more than seven times heavier than water; The boat carries goods such as food, machinery, construction equipment are much heavier than water.But it is so heavy that why is a boat able to float on the water? Object by buoyancy (F) = the density of the fluid (p) (g) * * gravity acceleration of the object displaces the liquid volume (V) is also a steel, density does not change, the same location (on earth) normally do not change; When steel ship displaces the liquid volume than by its own gravity, the F (floating) > G (gravity), the ship will rise. So, the same quality of steel, into a form, after displacement increases, can float; While knead into a ball will sink.

The sides of the tin box, of course, the water pressure at the same time, but it's the size of the pressure of the before and after the two sides are equal, in the opposite direction, cancel each other out; Also offset each other. The pressure of the left and right sides of buoyancy is increasing with the depth of the water, as part of object immersed in water volume increases. Because the volume of the iron box is much bigger than iron sheet, the weight of the row of boiled water is much bigger, and most of the buoyancy, so something in the box can float on water. Big ship can float on the water of truth is the same. The object the law, is the Greek scholar Archimedes discovered more than 2000 years ago, he said accurately, "role in water body of buoyancy is equal to the size of the object on the weight of the row of water". The greater the ship, draft, means that the weight of the ship tier boiled water is larger, the buoyancy of the ship is larger also, of course also can carry more stuff. Therefore, Archimedes's law can well explain to you: regardless of multiple ship, why is a boat able to float.