Physics question
Discussion
Now I think I already know the answer to this one but I'm not 100% sure. If you have a large iceberg that's floating around and it melts, does the level of the water increase or stay the same or sink? Or say a glass that's full to the brim with an ice cube in it, will it overflow when the icecube melts. I reckon it'd stay the same but am prob wrong.
Frozen water takes up more area than fluid water, if the ice is fully submerged under water (for the sake of simplicity) when it melts the waterline will recede.
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
chim_knee said:
My guess/stab-in-the-dark
The level will fall as ice is far more voluminous than water.
Am I right? :excitedface:
I think so.
Edit: No, hang on. I think it will remain the same as the iceburg displaces only the volume of water its density is equal to. So if *only* the but in the water melts the level would drop, but there's also the bit sticking out of the water that will also melt.
>> Edited by Mr E on Friday 17th February 16:30
JoolzB said:
Now I think I already know the answer to this one but I'm not 100% sure. If you have a large iceberg that's floating around and it melts, does the level of the water increase or stay the same or sink? Or say a glass that's full to the brim with an ice cube in it, will it overflow when the icecube melts. I reckon it'd stay the same but am prob wrong.
Two different problems there. With the ice cube in glass prob we need to know the temperature of the water before and after melting. Typically the water will cool and therefore the level will drop slightly. (all this assumes a pure water ice cube)
With the iceberg, it will depend on the amount of dust/debris on/in the iceberg. If there is some then the water level will drop very very slightly.
scorp said:
Frozen water takes up more area than fluid water, if the ice is fully submerged under water (for the sake of simplicity) when it melts the waterline will recede.
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
But shirley an iceberg an ice cube are the same thing? The reason it floats is that frozen water is less dense hence why the icebergs a floater. If Archimedes principle is taken into account then surely the level would stay constant?
Ice weighs less than water. That's why you have the top of an ice berg sticking out of the water. It's the same with an ice cube in a glass.
I'm thinking this through as I'm typing:
the iceberg displaces an amount of water equal to it's own weight. As the iceberg melts, it provides an amount of water equal to it's own weight. Therefore, the level remains constant.
Where we are talking about icebergs calving into the sea, or glaciers travelling into the sea, this is introducing new material to the ocean, hence the level will rise (but that wasn't your question, was it?).
I'm thinking this through as I'm typing:
the iceberg displaces an amount of water equal to it's own weight. As the iceberg melts, it provides an amount of water equal to it's own weight. Therefore, the level remains constant.
Where we are talking about icebergs calving into the sea, or glaciers travelling into the sea, this is introducing new material to the ocean, hence the level will rise (but that wasn't your question, was it?).
J1mmyD said:
Where we are talking about icebergs calving into the sea, or glaciers travelling into the sea, this is introducing new material to the ocean, hence the level will rise (but that wasn't your question, was it?).
No it wasn't but it did start off as that kindda thought. The polar melts are melt thawing from rock above sea level?
I think the term you're looking for is volume. The volume occupied by ice is greater than that of the same amount of water, hence if you put a full bottle of water in the freezer it will be more than liekly to break at the water freezes and the resulting ice tries to occupy more that the volume of the bottle. So in your case as the ice melts the level of the water in the glass would be less that full to the brim.
JoolzB said:
Frozen water takes up more area than fluid water, if the ice is fully submerged under water (for the sake of simplicity) when it melts the waterline will recede.
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
But shirley an iceberg an ice cube are the same thing? The reason it floats is that frozen water is less dense hence why the icebergs a floater. If Archimedes principle is taken into account then surely the level would stay constant?
Only stay constant if you assume no cooling of the surrounding medium AND there are no heavier than water partilses in/on the berg.
JoolzB said:
Frozen water takes up more area than fluid water, if the ice is fully submerged under water (for the sake of simplicity) when it melts the waterline will recede.
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
But shirley an iceberg an ice cube are the same thing? The reason it floats is that frozen water is less dense hence why the icebergs a floater. If Archimedes principle is taken into account then surely the level would stay constant?
I was thinking of a glass of coke with icecubes crammed into it (and thus forced to submerge, so bouyancy isnt a factor, but displacement is) im sure the physics of a free floating iceberg is a bit different though
>> Edited by scorp on Friday 17th February 16:37
TeamD said:
I think the term you're looking for is volume. The volume occupied by ice is greater than that of the same amount of water, hence if you put a full bottle of water in the freezer it will be more than liekly to break at the water freezes and the resulting ice tries to occupy more that the volume of the bottle. So in your case as the ice melts the level of the water in the glass would be less that full to the brim.
Yeah yer right but the iceberg/cube would be partially above the brim of the glass?
scorp said:
Frozen water takes up more area than fluid water, if the ice is fully submerged under water (for the sake of simplicity) when it melts the waterline will recede.
Its gets a bit more complicated if your talking icebergs since there is a bit poking out above the water.
>> Edited by scorp on Friday 17th February 16:28
But shirley an iceberg an ice cube are the same thing? The reason it floats is that frozen water is less dense hence why the icebergs a floater. If Archimedes principle is taken into account then surely the level would stay constant?
I was demonstrating my point with a fully submerged ice cube as it makes it easier to explain, when you have to deal with the bouyancy of the iceberg and how much water it displaces it complicates the explanation
Yes but it's absolutely fundemental to the question.
Ice is less dense than water. However, the fraction of the iceberg which will be displacing water is exactly equal to the ratio of densities of ice/water. When the ice melts it will all become submerged but it will also contract by exactly the right amount that water level will remain constant throughout.
I am pretty sure that is right. The melting polar ice caps thing would make levels rise because it is water that is currently on land being added to the sea?
and coke is more interesting and tasty than water.It would stay the same. Also the average temperature of the ice/water once the ice & water components had melted and merged would be equal to the average of the original temperature of the ice and the original temperature of the water. That is to say that the ice/water would have a greater density than the un-iced water before the cube was added.
For a practical example consider a cocktail with ice on it, filled very nearly to the brim, you sit there on a hot summers day chatting away to a friend as the ice melts....... now, what you'll know is that the cocktail glass doesn't overflow, nor sadly does it spontaneously get fuller.
For a practical example consider a cocktail with ice on it, filled very nearly to the brim, you sit there on a hot summers day chatting away to a friend as the ice melts....... now, what you'll know is that the cocktail glass doesn't overflow, nor sadly does it spontaneously get fuller.
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