Why don't big ships sink in the water?

Question

Why don't big ships sink in the water?

Answer 1

Ships will float as long as the weight of the water displaced is greater then the weight of the ship. So if a 300 ton ship displaces (the water that would be there if the ship wasn't) an amount of water that weighs 400 tons, it will float. They do this by having large hulls that displace a lot of water

Answer 2

buoyancy

Answer 3

The volume of water it displaces holds it up!! Poss millions of gallons.

Answer 4

It has air buoyancy in it.

Answer 5

cuz the lower part is hollowed

Answer 6

ANYTHING will float if it weighs less than the water it displaces.  You always hear discussions about the "displacement" of a ship--that means how much water moves out of the way when the ship is set down in the water, essentially not moving.

Answer 7

Becoz their CG (centre of gravity) lies within their base and the lower deck is loaded with sufficient amount of weight to keep it floating in water!

Answer 8

ballast?

theres air holds in ships

if those filled with water it would sink

Answer 9

Today, ships are made of steel and lots of heavy stuff. Some can weigh around 80, 000 tons. How can any of them possibly stay afloat? The reason is simple, and you can make your own ship float too.

All you need is:

aluminum foil,

a few paper clips,

an empty aquarium (or similar large container)

and water

  

Here's what you do:

Partially fill the aquarium or container with water.

Take the aluminum foil, bend it in half and make a boat. Does it float?

Add a few of the paper clips. Now, what happens?

Take another sheet of aluminum and tightly fold it in half, placing the same number of paper clips as in the first boat inside the flattened one. What happens?

Here's how it works:

The aluminum in the boat shape displaces more water than the flattened one. If the object has enough volume to displace an amount of water equal to its own weight, it will float. Its weight, or the force of gravity, will equal its buoyancy, or the force of the water pushing up on it.

Answer 10

principle of buoyancy

http://ffden-2.phys.uaf.edu/211_fall2002...

Answer 11

These ships are heavy, but they're also huge, and not just a big, solid chunk of metal. There is plenty of "space" in a boat or ship. This space is filled with air, which we know is lighter than water.

This leads to the discussion of two concepts; displacement and buoyancy.

Displacement refers to the volume of water the ship displaces (moves out of the way) or the weight of the water displaced - depending on context.

Buoyancy - as "discovered" by Archimedes is what actually makes the boat/ship float. This is the upward force applied by the water. (The water is trying to fill the void created when the ship displaces the water, so it's pushing against the hull.)

The boat only displaces water EQUAL to its weight. If you've taken a statics class this is easy to figure out. Forces have to be balanced or else the object moves until equilibrium is achieved. The weight of the vessel is equal to the weight of the water the hull is displacing. However the boat has reserve buoyancy - typically on a small boat that means that the vessel sits high enough in the water that adding extra weight (thereby lowering the boat in the water) does not cause the edges of the hull to sink dangerously close to the water level. In larger vessels there are water tight tanks, called ballast tanks, which can be filled with water or emptied to adjust the weight of the vessel. this maintains the displacement of the vessel even as it changes the weight of cargo it is carrying.  Ballast is the added weight though, so saying that ballast makes a ship float is not accurate.

Answer 12

Two reasons: large surface area and ballast

The principle's pretty simple to demonstrate; fill a sink about half way and put a glass in there so that it floats. Now drop small objects into the glass and you can observe it becoming increasingly steady in the water as the weight increases

Big ships have a huge ammount of ballast at the bottom which keeps their centre of gravity low and stops the ship from tipping over

How well something floats isnt neceserrily determined by their weight but mainly by it's surface area. For example; if a piece of paper is put in the water on its edge then it has a very low surface area and all the weight is concentrated on a tiny area. It won't balance and sink. If, however, you lay the paper flat in the water the weight is spread out very evenly over a much larger area and can even carry other objects

Hope that's helped you understand it

Answer 13

things submerged in water buoyancy level is

determined by the weight of the fluid displaced,

not the weight of the actual object.

also, the curved shape of the bottom of the boat keeps it from

sinking too far beneath the water.

Answer 14

boats have a certain shape. make a boat out of clay and put it in water, then make a ball from the clay and put it in water

Answer 15

Here' is a better question

The titanic was made out of metal, metal is stronger than ice. Still think it suck by hitting an iceberg? For more proof that the Titanic was a lie, check my source.

Answer 16

ever hear of the titanic?   they often do sink.

Answer 17

Imagine a ship floating in the water.  Then imagine that the ship turns invisible.  You will see a hole in the water where the ship is sitting and pushing water aside.  The volume of the water in that hole must be heavier than the volume of the portion of the ship taking up space in that hole in order for it to float.

Answer 18

yup, there's air sealed up inside the hull of the ship, air is lighter than water, therefore it resists sinking, if the ship was filled with water, then it would sink.