Buoyancy Force application

How does boat float on the water?

Boats which are very big and heavy can float on the water, but needles are drowned at water. Why?

Every material in fluid (such as air and water) has buoyancy force. The direction of buoyancy is always upward. It means if buoyancy force is bigger than weight of the object, it will float.

When we put empty plastic bottle on the water, it will floats. This is because of the buoyancy force is bigger than weight of the bottle. Actually, there is small portion of bottle that drowned, but it is the key how it can float. Pressure occurs inside water with any direction. This pressure increases as the depth of water. Force can be formed if there is a surface in the water. As we know, pressure is force divided by area.

Buoyancy forces are formed by this phenomenon. Archimides principle said that buoyancy force is directly proportional with drowned volume. Mathematically, Buoyancy force is: F = ρ . g . V, where ρ is the density of fluid (water), g is gravity, and V is volume which is drowned.

Boat can float on water based on this principle. Boat has hull to get buoyancy force and makes the boat float. So it is very important to keep hull safe. In the sea, corals are sometimes found in the sea. Hull can crash the coral and causes the hull leakage. This condition can causes boat drowned since hull is the source of buoyancy force.