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DF3VI > INFO 21.07.02 11:55l 43 Lines 1617 Bytes #999 (180) @ WW
BID : L7CDB0OVN00P
Read: DB0FHN GUEST
Subj: Re^2: balloons (G0TEZ)
Path: DB0FHN<DB0ZWI<DB0HOT<DB0MRW<DB0ERF<DB0ROF<DB0AIS<DB0NDK<DB0ACH<DB0OVN
Sent: 020721/0944z @:DB0OVN.#NRW.DEU.EU [BCM West<>Link - Neuss] bcm1.46 LT:180
From: DF3VI @ DB0OVN.#NRW.DEU.EU (Patrick)
To: INFO @ WW
X-Info: Sent with login password
G0TEZ babbled:
>Helmut,DK2ZA said:
>>
>> There is a subtle but significant error in Ian's (G0TEZ) statement:
=================
>>
>> >> Helium is twice the density of Hydrogen so there is only
>> >> half the lifting force ..
======================
>>
>>
>> The densities of air, helium and hydrogen at 1.0132 bar and 0 DEG Celsius
>> are 1.293, 0.178 and 0.09 kilograms/cubic meter.
>>
>>
Oh no, that is NOT what DK2ZA said - at least not everything.
Ian, is that british fairness to misquote and to leave away the main part?
Please read the comment of DK2ZA completely and UNDERSTAND it,
don't stop after reading the first lines (and then stop thinking).
Your error is not in the density, but in the LIFTING FORCE in air.
The absolut density of helium and hydrogen is irrelevant, what counts
is the RELATIVE density to air, which is the surrounding media.
(Everything is relative - Einstein)
The lifting force of 1 cube meter helium is about 11N,
the lifting force of 1 cube meter hydrogen about 12N,
that's not twice, but less than plus 10 per cent...
73
y
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: Patrick ! !__! DF 3 VI !__! @ DB0OVN !__! JO31FH !__! G21 !
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