An amount that weighs as much as the ship does.
The displaced water should also weigh 450 N.
To float 1 pound in water, you would need to displace 1 pound of water. This is because of Archimedes' principle, which states that the buoyant force acting on an object is equal to the weight of the fluid displaced by the object. So you would need to displace enough water to counteract the weight of the 1 pound object and make it float.
Quick and dirty answer: Because they are built to be essentially hollow, they are much larger in volume than the water they displace, and so in effect they are much less dense over all than the water they displace.
Provided the boats and the ships displace their weight in water without the water coming inboard, they will float and not sink. A boat made of wood is likely to float even when full of water because wood tends to float. It is all to do with displacement and freeboard.
Wood and styrofoam float because they are less dense than water, which causes them to displace enough water to create an upward force called buoyancy. The buoyant force counteracts the gravitational force acting on the object, allowing it to float on the water's surface.
20,000 cubic kilometres
the weight of the ship is equal to the amount of water displaced
The displaced water should also weigh 450 N.
You must displace as much water at the metal weighs. So there is equillibrium between the metal and the water.
It must displace as much weight in water as it weighs (roughly 600 cubic meters of water). These boats have huge hulls, so can easily displace this much without beginning to sink.
To float 1 pound in water, you would need to displace 1 pound of water. This is because of Archimedes' principle, which states that the buoyant force acting on an object is equal to the weight of the fluid displaced by the object. So you would need to displace enough water to counteract the weight of the 1 pound object and make it float.
The same way anything floats, by displacing an amount of water that weighs as much as it does. Airplanes that are meant to float on water typically either have boat-like hulls or floats whose purpose is to displace enough water to allow the airplane to float.
Quick and dirty answer: Because they are built to be essentially hollow, they are much larger in volume than the water they displace, and so in effect they are much less dense over all than the water they displace.
The boats displace water in such a way that they remain afloat. Hence why most boats have a V hull shape. This allows them to displace the water and remain afloat, if on the other hand you put to much in a boat it will eventually sink.
Provided the boats and the ships displace their weight in water without the water coming inboard, they will float and not sink. A boat made of wood is likely to float even when full of water because wood tends to float. It is all to do with displacement and freeboard.
Wood and styrofoam float because they are less dense than water, which causes them to displace enough water to create an upward force called buoyancy. The buoyant force counteracts the gravitational force acting on the object, allowing it to float on the water's surface.
Objects with higher densities than water will sink, while objects with lower densities will float. Density is a measure of how much mass is packed into a given volume, so a denser object will displace less water and sink, while a less dense object will displace more water and float.