The submarine is another application of 'Archimedes Principle'. On surface, the submarine floats, with its conning tower and most of the deck, being clear of the water.
The boat is provided with large ballast tanks which can be filled with water. This increases the weight of the submarine, so that it sinks into the sea, so that it sinks lower.
Horizontal rudders are titled to make the submarine drive downwards when the tanks are practically full and the boat is ready to submerge. When the submarine is ready to surface, the rudders are moved to drive the boat upwards, and compressed air is forced into the ballast tanks to drive the water out so that the submarine can rise.
Most of the marine animals also use this principle to remain at a selected level in the sea. For example, fish has an air sac, called a swim bladder in its body. This is filled with air and usually occupies about 5 per cent of its total body volume. Its size is adjusted so that the fish is posed at the depth at which is usually lives and feeds. At that level, the condition of its weight is exactly balanced by the upthrust it experiences. To swim up and down the fish uses fins.
No comments:
Post a Comment