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[PUBLIC] Physics Question - The Cover Story
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Wed, Oct. 4th, 2006 02:05 pm
[PUBLIC] Physics Question

A bizzare question just came up I don't have a good answer for:

The bouyancy of an object is determined by its density vs. the density of the medium it rests in. So riddle me this: If one constructs a rigid box 1 cubic meter in size out of such a material that the structure of the box weighs less than 1.2 kilograms or so, and then evacuates any atmosphere from within the box, will it float in the air like a balloon? My gut says no, but I can't figure out why. Any hints?

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Current Location: Omaha, NE

4CommentReplyShare

teenyweenyowen
Owen
Wed, Oct. 4th, 2006 08:06 pm (UTC)

Hint: Zeplin


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sirroxton
sirroxton
Adam Augusta
Wed, Oct. 4th, 2006 10:50 pm (UTC)

I think the answer is that it *will* float. It's just extremely difficult to create a device that's light enough that can stand crushing atmospheric pressures.


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sirroxton
sirroxton
Adam Augusta
Wed, Oct. 4th, 2006 11:04 pm (UTC)

Incidentally the buoyancy of vacuum is only trivially better than hydrogen or helium.


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(Anonymous)
Tue, Oct. 10th, 2006 08:37 am (UTC)
It'll float

An object sinks if the weight of the fluid it displaces is less than the weight of the object itself. The density of air being > 1.2Kg per cubic metre, this is not true. Therefore it will float.

The vaccum only helps it along.

~Manjit.


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