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Author Topic: How much O2 is needed to lift a 1kg mass in water?  (Read 3009 times)

Fiona

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Fiona  asked the Naked Scientists:
   
Hi Chris, really love your site.  Need some help with a coefficient for:
 
In water (ie a lake), how much O2 is needed to lift 1 Kg of Mass?
 
Thanks for your assistance.
Best Regards
Fiona

What do you think?
« Last Edit: 19/04/2011 11:30:02 by _system »


 

Offline RD

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« Last Edit: 19/04/2011 12:14:53 by RD »
 

Offline Phractality

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How much O2 is needed to lift a 1kg mass in water?
« Reply #2 on: 19/04/2011 16:38:13 »
To float, the 1 kg mass plus the mass of O₂must displace an equal or greater mass of water. So the mass of O₂depends on the density and depth of the water and the density of the 1 kg mass. If you have a balloon full of O₂which is just big enough to make the 1 kg mass float at the surface, and you then pull it below the surface, the balloon will shrink as the pressure increases. Below a certain depth, it will sink.
 

Offline JP

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How much O2 is needed to lift a 1kg mass in water?
« Reply #3 on: 19/04/2011 16:43:56 »
You need no O2 to make 1 kg of ice float.  :)

(Which is due to it's density being lower than water, as others have pointed out.)
 

Offline Geezer

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How much O2 is needed to lift a 1kg mass in water?
« Reply #4 on: 19/04/2011 20:16:36 »
I don't think we have enough information to answer the question. As Phrac points out, the lift is a function of the depth, so, if you want to lift something from the bottom of the lake, you'll need to know how deep the lake is.
 

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How much O2 is needed to lift a 1kg mass in water?
« Reply #4 on: 19/04/2011 20:16:36 »

 

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