Subject:
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Re: LEGO RCX Skydivers
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Newsgroups:
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lugnet.robotics
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Date:
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Tue, 9 Nov 1999 22:15:19 GMT
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Original-From:
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Pete Hardie <PETE.HARDIE@DVSGantispam.SCIATL.COM>
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Viewed:
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743 times
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Robert Munafo wrote:
>
> Either my calculations are wrong, or you have a different concept of what is a
> "staggering" amount of helium. Here are my calculations:
>
> Each gram-mole of gas at STP [1] takes up 22.41 liters (cubic decimeters) of
> space.
>
> The weight of a mole of air is about 28 grams (a little more actually, but I'm
> being generous), and the weight of a mole of helium is 4 grams; thus the net
> bouyancy per mole of helium is 24 grams [2]
>
> Net bouancy per liter of helium = 24 / 22.41 = 1.07
>
> Volume of a sphere 1 meter in diameter is 4/3 pi r^3, where r is 5 decimeters,
> which comes out to about 523.6 liters.
>
> So a spherical balloon of 1-meter diameter and filled with helium would have
> about 560 grams of bouyancy, or about 19 ounces for you non-Metric dudes.
>
> For comparison, the "fish" blimp that swam around in the Media Lab during its
> first year or two was about 2-3 times this volume (same diameter but about 3
> times the length)
>
> What am I missing?
Mostly my hyperbole....
Still, getting envelopes for that amount of helium is difficult.
--
Pete Hardie | Goalie, DVSG Dart Team
Scientific Atlanta |
Digital Video Services Group |
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Message has 1 Reply: ![](/news/x.gif) | | Re: LEGO RCX Skydivers
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| (...) What about from Edmund Scientific? --- Chris Osborn FozzTexx Enterprises 707 226 7629 - Voice 2136 Coronado Ave. 707 581 1797 - Fax Napa, CA 94559 <fozztexx@fozztexx.com> (URL) (25 years ago, 9-Nov-99, to lugnet.robotics)
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Message is in Reply To:
![](/news/x.gif) | | Re: LEGO RCX Skydivers
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| Either my calculations are wrong, or you have a different concept of what is a "staggering" amount of helium. Here are my calculations: Each gram-mole of gas at STP [1] takes up 22.41 liters (cubic decimeters) of space. The weight of a mole of air (...) (25 years ago, 9-Nov-99, to lugnet.robotics)
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22 Messages in This Thread: ![LEGO RCX Skydivers -Ian Sinclair (5-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif) ![](/news/246.gif) ![Re: LEGO RCX Skydivers -Phillip Ogden (5-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -Soh Chio Siong (5-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -lego-robotics@crynwr.com (Jean auBois) (5-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -Jack Gregory (5-Nov-99 to lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -lego-robotics@crynwr.com (Christian Jacobsen) (5-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -Robert Munafo (6-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -lego-robotics@crynwr.com (Pete Hardie) (8-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -Robert Munafo (9-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![You are here](/news/here.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -lego-robotics@crynwr.com (Chris Osborn) (9-Nov-99 to lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/68.gif) ![Re: LEGO RCX Skydivers -Jonathan Brown (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif) ![](/news/246.gif) ![Re: LEGO RCX Skydivers -Ian Sinclair (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/x.gif) ![](/news/68.gif) ![Re: LEGO RCX Skydivers -Marco Berti (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: LEGO RCX Skydivers -Jonathan Brown (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif) ![](/news/246.gif) ![Lego TV -Rich Thompson (6-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![Re: Lego TV -Robert G. Fay (6-Nov-99 to lugnet.robotics)](/news/x.gif) ![](/news/46.gif) ![RE: Lego TV -Rich Thompson (6-Nov-99 to lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -lego-robotics@crynwr.com (Andy Gombos) (6-Nov-99 to lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -Marco Berti (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/x.gif) ![](/news/268.gif) ![Re: LEGO RCX Skydivers -Rick Kirkwood (6-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
![](/news/x.gif) ![](/news/x.gif) ![](/news/68.gif) ![Re: LEGO RCX Skydivers -Jonathan Brown (7-Nov-99 to lugnet.general, lugnet.robotics)](/news/x.gif)
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