(talking of ice bergs)
2007-11-24 00:09:46 · 11 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Ice floats because it is less dense than the liquid water it displaces. Needles (which are metal) are more dense than water so they sink. It's called Archimedes's Principal.
Usually, the solid form of a molecule will be more dense than the liquid form. This is not true with ice, because of its crystalline structure.
2007-11-24 00:13:21 · answer #1 · answered by Zelda Hunter 7 · 6⤊ 0⤋
The ability to float has nothing to do with size or weight. It has to do with displacement.
This just means that an object will float if it displaces (pushes away) a weight of water equal to itself. It has little to do with the composition or weight of the object and more to do with its shape.
For instance, a 10-ton piece of metel has trouble floating, unless it is shaped into a boat.
The very nature of ice allows it to float in any shape. This is because its molecules are arranged in a pattern that is less dense than that of water.
2007-11-24 00:34:24 · answer #2 · answered by pumpkin head 4 · 0⤊ 0⤋
The surface area of the ice is a lot greater. Therefore the displacement and density of the ice is actually less than that of the pin. (The density of ice is less than water-fact) A pin can float on STILL water, as long as it is carefully placed on the skin of the water, but in the ocean waves easily lift the pin out of place, and it is more dense than water. Ergo, the sinking of the pin.
2007-11-24 00:27:59 · answer #3 · answered by hahahahahaha 1 · 0⤊ 1⤋
Because ice is less dense than water (and steel is MUCH denser than water).
Interestingly, water is one of the very few substances that expands as it gets colder. This is why ice floats in water. If this didn't happen many fish would die in frozen ponds and lakes every winter as the ice would cover all food sources (weeds etc.) on the bottom.
2007-11-24 00:16:39 · answer #4 · answered by breeze_sf 1 · 1⤊ 0⤋
due to the amazing property that water posesses, called hydrogen bonding, water in its solid state (ice) is less dense than in its liquid state. not many substances have this property.
needles, are made from stainless steel, or other alloys, which have a density far greater than that of water, and they tend to sink.
archimedes principle states that the bouyant force acting upwards on an object is proportional to the volume of water that it displaces, since density is inversely proportional to volume, an object with a large density (hence a small area, or large mass), will be resisted with less bouyant force from the liquid, and will sink due to its self weight.
2007-11-24 01:28:21 · answer #5 · answered by brownian_dogma 4 · 0⤊ 0⤋
Because ice is positively buoyant, it doesn't matter how much it weighs, the water it displaces weighs more than it, therefore it floats.
A better question would be, how does a ship weighing hundreds of tons, and made of steel just like the needle, float?
Steel itself is not positively buoyant, however, a ship is not a solid chunk of steel, there are air spaces within, so once again, the water it displaces weighs more than it, therefore it floats.
2007-11-24 00:17:40 · answer #6 · answered by Random Malefactor 5 · 0⤊ 1⤋
the mass of the needle is greater than both the buoyancy of it and the mass of the water. Ice is water as a solid. Water molecules are spread out and the mass of the water is distributed over a bigger volume
2007-11-24 00:15:29 · answer #7 · answered by jgonzos6 4 · 0⤊ 2⤋
Because metal has a higher density than water. Ice is made of water, which would be the same density, that's why it floats.
2007-11-24 00:14:00 · answer #8 · answered by icicle_tulip 1 · 2⤊ 2⤋
its the ration of mass & volume to weight. The needle is hollow, so there is nothing bouyant to keep it afloat.
Ice on the other hand, expands and gains volume so it tends to be lighter than what it was made from.
2007-11-24 00:14:07 · answer #9 · answered by Fancy That 6 · 0⤊ 2⤋
Because air is trapped, in tiny bubbles, inside the ice.
2007-11-24 00:12:31 · answer #10 · answered by Moorglademover 6 · 1⤊ 4⤋