how do ships having tons of weight float on water
Answers
Answer:
But because of its body design, which contains a lot of air, it displaces (pushes aside) enough water so that the buoyancy force is equal to its gravity force. That is why a ship floats. ... So if a ship weighs 1000 tonnes, it will sink into the water until it has displaced 1000 tonnes of water.
Explanation:
Ships float for two reasons: the weight of the amount of water they push out of the way is equal to their overall weight, and they are stable.
If a ship could not push enough water out of the way, it would sink. If a ship is not properly stabilized or balanced (too much weight forward, aft, or up high), it will flip over and sink.
Gravity pulls down on a ship just like everything else; it wants that ship to sit on the bottom of the sea. Water exerts a force on the ship, holding it up on the surface. The force of the water is equal to the weight of the amount of water displaced. One cubic foot of fresh water weighs 62.4 pounds, and sea water weighs 64 pounds per cubic foot because of all of the dissolved salts in it. So for every cubic foot of sea water that a ship pushes out of the way, the water pushes back with the equivalent of 64 pounds of force.
Let's take a 1 foot long by 1 foot wide by 1 foot tall ship, or rather a little box barge. The sides and bottom are solid but the entire interior is just air, so even if its made out of steel or iron (pretty heavy stuff), it probably would weigh only a 10 to 20 pounds. This is much less than the 64 pounds that solid cubic foot of water weighs, so it should float. The next step is the balance or stability. If it doesn't displace enough water or if it's weight is not properly distributed, it will be unstable.
Let's change the dimensions to 6 inches long by 6 inches wide by 48 inches tall. Kind of a ridiculous looking vessel but this is just an example. The volume is the same, 1 cubic foot (1,728 cubic inches) but it's stability and balance will be completely different. Let's keep a similar weight of 20 pounds. This 20 pound vessel will sink down 15 inches in the sea water to equalize its weight with the weight of water.
(6 inches x 6 inches x 15 inches x the weight of water of .037 pounds per cubic inch = 20 pounds of water)
This will leave 33 inches left sticking out of the water. The slightest breeze or ripple in the water will topple this vessel over and suddenly instead of being 6 inches long it will be 48 inches long. If it has an open top, it will quickly fill with water and sink. Even though it displaced enough water to theoretically float, it actuality it was unstable, flipped over, and sank.