How do submarines work?
Submarines are incredibly complex machines, and understanding how they work can give you quite an insight into the world of physics. Not only do submarines have to navigate and propel themselves across the vast ocean’s surface, they have the added dimension of depth to worry about. Diving and Surfacing In order for a submarine to dive and surface, it must achieve negative and positive buoyancy, respectively. This means that the submarine is either more dense or less dense than the water, which cause it to either sink or float. The submarine accomplishes this by alternately filling its ballast tanks with air or water, or a mixture of both. When the submarine is on the surface, the ballast tanks are filled with air. When the submarine needs to dive, its tanks are filled with seawater, causing it to achieve negative buoyancy and sink. By regulating the mixture of air and water, the submarine can dive to a very precise depth.
The diving and surfacing of the submarine has got to do with the buoyancy of water. Buoyancy is a force exerted upwards when a foreign body or mass is immersed in water. The Archimedes’ Principle states that the force of bouyancy is equal to the weight of water that is displaced by the foreign object. If this force is equal to the weight of the object then it will become weightless and float in the water. But if it is less than the weight of the object then it will sink in the water. This is the basis of the principle on how the submarine works. Submarines are built with buoyancy tanks which can be filled with adjustable amount of air or water that are wrapped around its body. A submarine at the bottom can be made to float by pumping compressed air into the tanks causing the sea water to come out and increases the buoyancy of the submarine.
Submarines are built to be nearly zero buoyant meaning that the volume of the submarine weights just slightly less than the same volume of water. Tanks spaced strategically in the submarine are filled with water to make the submarine slightly heavier, causing the submarine to sink. Bow planes are small wings, designed to make the submarine “fly” throught the water. The captain sends the ship up or down by directing the crew to change the buoyancy and by manuvering the bow planes.
