How do big ships float?
108792
They are made of wood, which floats because it has a lower density than water.  If you made a ship out of solid gold, it would sink, for example.
698894
An object will float in water if its density is less than the density of water.  Solid steel is more dense than water so it sinks.\nA steel boat is hollow and filled with air.  Its average density is less than a solid piece of steel.  If this average density is less than water the boat will float.  Of course if the boat becomes swamped  (filled with water) then the average density increases and the boat sinks.
90516
This can be done with a density gradient column.  It is made of 2 fluids that are carefully mixed so that the density of the mixture varies from the top of the container to the bottom.  An object will then come to rest where its density matches the mixture.  This is actually a very accurate way of determining the density of materials.  However, over time the fluids in the column mix by diffusion and will eventually cause the suspended objects to sink or float.
378932
First of all, the word moon-pool is a kind of drilling oil wells in the sea-beds. Since the oil gathering (or collecting) ship has a pool inside to collect all oil from the wells and separate the water below the oil, the pools in entertainment ships sometimes are called moon-pool as they are almost similar in shape.\nSecond, either its structure is a simple space inside the ship board or a specially designed one, the ship can bear the weight completely. It's important to note one thing: the ship itself is made of tons of steel; so why it does not sink? It doesn't make any difference if the weight on ship is due to goods, persons, cargos, or water. As far as the specific gravity of the segment of ship inside the water is equal one (or almost), the ship floats. So the design of lower parts of ships are so that there is a large amount of free space (atmospheric rooms) which balance the weight per volume. A common ship with length of about 50m and height of 3-5m normally can carry loads of about 5000 tons; and the total weight of water in a pool with 15x8x4m dimensions is only 480 tons (i.e. less than 10% of payload)
218971
Any object will float as long as it displaces a volume of liquid that is more massive than itself. Take the aluminum boat and fold it into a block of aluminum and it sinks. But due to the shape of the boat, the mass of the aluminum,plus you, and your fishing gear, is still less than the volume of water pushed aside by the hull of the boat. So, you float.
695854
To 'float' you don't need any forces.  To stay in an orbit you need the force of gravity.  All mass has gravity.  Where gravity comes from is difficult to say.  Physicists are grappling with string theory to describe this one.
236062
Because of its shape. \n\nA ship, when placed in water, forces some volume of the water to move (displace) and make place for the ship. If the weight of the displaced water is more than that of the ship, the ship will float. \n\nIn other terms, the average density of the ship is less than that of water and hence it floats on water.
905607
make a little "boat" that you can add weights to and float it in the different liquids.  Gradually add weight to the boat in each liquid to see how much it can hold before it sinks.  The more weight the boat can hold, the greater the density of the liquid!\n\nThis is basically a poor-man's hydrometer.
39301
Think of it this way:  If an object weighs more than it would if it was made of water, it will sink.  If an object weighs less that it would if it was made of water it will float.\n\nA coin is made of solid metal which makes it denser than water, therefore heavier.  It will sink.  A ship is made of metal also, but NOT solid metal.  It also consists of other materials but mainly air (inside the ship).  This means it's lighter than water, which is why it will float.
481877
Your other answerers are on the right track.  When a boat floats, it displaces a volume of water with a weight equal to the weight of the boat.\n\nSo, the heavier the liquid in which the boat is floating, the less liquid it must displace in order to float, and thus, the higher it will float.\n\nThis means that the basic question is which is more dense (and so, heavier), saltwater or freshwater.  And, the answer is that saltwater is somewhere between 2.5% and 3.5% more dense than freshwater.
743392
it always floats.  take a look at any type of oil spill, the authorities that take care of it float a ring around the spill to stop it from spreading. these rings are called Booms. they are barriers that float on top of the water or are dragged beside or behind vessels and are the most common type of equipment used to control the spreading.  These mechanisms float on the surface and have three main parts:  a 'freeboard' or part that rises above the water surface and contains the oil and prevents if from spilling over, a 'skirt' that rides below the surface and prevents the oil from escaping under the boom, and a chain or cable that connects, strengthens, and stabilizes the boom.  Connected sections of the boom are placed around the oil spill until the pollutant is completely surrounded and eventually contained.
563919
Assuming that the cardboard is water tight:\n\nBuoyancy force = Weight of water displaced\n\n(mass of boat)*g = (desity of water) * 4ft*5ft * height * g\n\n81820g = 1g/cm^3 * 18581 cm^2 * height\n\nheight = 4.4 cm, which is the waterline when the boat weighs 180 pounds.\n\nYeah, it sounds quite unbelievable, but most boats that large with a height of 1 foot can hold over 1100 pounds of weight before completely sinking.
80144
Center of gravity of the displaced liquid is the center of bouyancy. The (resultant) weight of the vessel acts at the center of gravity(downwards) and the (resultant) bouyant force acts at the center of bouyancy upwards.\n\nIt is better to have the center of gravity lower than the center of boyancy. for stabality. The lower it is the more stable.\n\nThis is because, if the vessel is tilted, the weight and the bouyant force make a couple. This can be against the tilt or with the tilt. If center of bouyancy is lower than center of gravity, it will tilt more. And vice versa.\n\n YOu can find this out by drawing small diagram of the forces.\n\nAlso you can try this. \nTake a pencil. \nhold it vertical but little tilted. \nnow assume, the bottom end is center of bouyancy and top end is center of gravity.\n\nso, push up form the bottom and push down form the top. You will see that the pencil becomes horizontal. i.e you ship sinks.\n\nIf you assume the opposite - take the top to be the center of bouyancy. Pull the top up and the bottom down. The pencil straightens. YOur ship stabalises.
429114
coz the principle of bouyancy comes into action. that is there is a space with air in the bottom part of the ship/boat n hence it doesnt allow it to sink.. n that too that a greater surface area is there so the pressure is distributed over a larger area. \n u can also call it Upthrust.\nexplanation-\nArchimedes discovered the law of bouyancy. It states: on everybody emersed in water (or fluid in general) there acts an upward force with magnitude equal to the wieght of displaced water/fluid.\n\nthere are 3 scenarios for a body in water:\n\n1. floats on the surface; gravity of the body equals bouyancy and equals exactly the amount of weight of the displaced water\n\n2. the body is entirely emersed in water; again gravity = bouyancy\n\n3. the body sank; gravity = boyancy + normal reaction of the floor.
294040
Things float as long as the water they displace (move out of the way) weighs as much as they do. Whether that happens depends on the density of the thing. The density of an object is equal to its weight divided by its volume. Every substance, including water, has its own density at a given temperature (density can vary as a substance gets hotter or colder). Any substance that is less dense than water floats while one that is more dense sinks. However, even though cargo ships hold a ton of heavy cargo, they have chambers of air inside that make them mostly hollow. This brings me to the main point... an object that is hollow like a cargo ship floats if its density-its weight divided by its total volume is less than the density of water.
257654
Say the anchor weighs 15 pounds in air and displaces 2 pounds of water.\nBefore the drop, the boat displaces its weight plus the 15 lb weight in air of the anchor. This is the maximum displacement situation, so the water is at maximum height.\nAfter the drop, if the anchor hits bottom, the boat displaces its weight only and the anchor displaces 2 lb of water, the minimum displacement situation, so the water is at minimum height.\nAfter the drop, if the anchor doesn't reach the bottom, the boat displaces its weight plus the 13 lb weight in water of the anchor. The anchor displaces 2 lb water. The total displacement is the same as the maximum displacement situation, so the water is at maximum height.
785776
I did this a long time ago at a science fair.  You need a small glass tube, like a test tube, but not too big.  Put a weight around the opening so it will float with the open end down.  The tricky part is to adjust the weight in the tube to it just floats.  Another way is to adjust how much water is in the tube when it is floating.  Put it in a plastic bottle with enough water to allow for submerging and surfacing.  (They don't like the work "sink" on submarines.)  To make the tube submerge, squeeze the bottle.  This compresses the air inside the tube.  The air takes up less space, provides less floatation and it submerges.  Release the bottle and the tube rises again.  It was acutally a lot of fun when I did it.