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Re: too easy?

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On 2023-08-15 17:17:38 +0000, RichD said:

> On August 13,  J. J. Lodder wrote:
>>>> In horizontal flight there are four forces,
>>>> Lift Drag, Thrust and Weight.
>>>> For steady horizontal flight Thrust must equal Drag,
>>>> and Lift must equal Weight.
>>>> For a real wing L/D will be about 10.
>>>> So to move through the air at speed v requires a power P of v times D.
>>>> So the fundamental equation for steady horizontal flight is
>>>> v = L/D . P/W, or P = vWD/L
>> 
>>> You forgot buoyancy B. The atmosphere is liquid.
>> 
>> Bzzzzzzttttttt!
>> The weight in the above is the -effective weight in air-.
>> The equation above does also cover balloons and Zeppelins.
>> It simplifies to T = D and v = P/D for Zeppelins, (at incidence = 0)
>> And you are confusing 'liquid' and 'fluid'.
> 
> Aluminum is heavier than water, it sinks. But if you pump air into
> a tank, it becomes buoyant.   Ask a scuba diver, they're
> experts on fluid mechanics, their lives depend on it.

That bit's OK, but ...
> 
> Ditto with the atmosphere -

... this bit is crazy. You can pump as much air as you like into an 
aluminium tank and it won't float away.


-- 
athel -- biochemist, not a physicist, but detector of crackpots

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too easy? nero <oldogf@yahoo.it> - 2023-08-09 17:17 -0700
  Re: too easy? whodat <whodaat@void.nowgre.com> - 2023-08-09 20:51 -0500
  Re: too easy? whodat <whodaat@void.nowgre.com> - 2023-08-09 21:48 -0500
    Re: too easy? nero <oldogf@yahoo.it> - 2023-08-10 16:45 -0700
    Re: too easy? nero <oldogf@yahoo.it> - 2023-08-10 16:48 -0700
  Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-10 11:37 +0200
    Re: too easy? nero <oldogf@yahoo.it> - 2023-08-10 16:52 -0700
      Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-11 12:53 +0200
    Re: too easy? nero <oldogf@yahoo.it> - 2023-08-10 16:54 -0700
    Re: too easy? RichD <r_delaney2001@yahoo.com> - 2023-08-12 12:01 -0700
      Re: too easy? whodat <whodaat@void.nowgre.com> - 2023-08-12 14:16 -0500
        Re: too easy? Volney <volney@invalid.invalid> - 2023-08-12 17:31 -0400
        Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-13 10:34 +0200
      Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-13 10:34 +0200
        Re: too easy? nero <oldogf@yahoo.it> - 2023-08-13 18:19 -0700
          Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-14 10:30 +0200
        Re: too easy? RichD <r_delaney2001@yahoo.com> - 2023-08-15 10:17 -0700
          Re: too easy? Athel Cornish-Bowden <athel.cb@gmail.com> - 2023-08-15 21:02 +0200
          Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-15 23:38 +0200
            Re: too easy? RichD <r_delaney2001@yahoo.com> - 2023-08-16 09:25 -0700
              Re: too easy? Prokaryotic Capase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2023-08-16 09:47 -0700
              Re: too easy? Paul Alsing <pnalsing@gmail.com> - 2023-08-16 17:51 -0700
                Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-17 09:45 +0200
                Re: too easy? patdolan <patdolan@comcast.net> - 2023-08-17 11:31 -0700
              Re: too easy? Tom Roberts <tjoberts137@sbcglobal.net> - 2023-08-17 13:03 -0500
  Re: too easy? Sylvia Else <sylvia@email.invalid> - 2023-08-11 11:40 +1000
    Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-11 12:53 +0200
      Re: too easy? Prokaryotic Capase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2023-08-11 11:02 -0700
        Re: too easy? patdolan <patdolan@comcast.net> - 2023-08-11 11:33 -0700
          Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-11 21:01 +0200
        Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-11 20:54 +0200
          Re: too easy? Prokaryotic Capase Homolog <prokaryotic.caspase.homolog@gmail.com> - 2023-08-11 14:38 -0700
            Re: too easy? nospam@de-ster.demon.nl (J. J. Lodder) - 2023-08-12 12:07 +0200
    Re: too easy? nero <oldogf@yahoo.it> - 2023-08-18 18:38 -0700

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