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From: djw1@ukc.UUCP (D.J.Webb)
Newsgroups: net.physics
Subject: Re: Monkey Query and new problem
Message-ID: <350@ukc.UUCP>
Date: Tue, 5-Nov-85 12:50:49 EST
Article-I.D.: ukc.350
Posted: Tue Nov  5 12:50:49 1985
Date-Received: Sun, 10-Nov-85 08:51:13 EST
References: <705@sri-arpa.ARPA> <661@petrus.UUCP> <10855@ucbvax.BERKELEY.EDU> <668@petrus.UUCP>
Reply-To: djw1@eagle.UUCP (Dave Webb)
Organization: U of Kent at Canterbury, Canterbury, UK
Lines: 17

In article <668@petrus.UUCP> mwg@petrus.UUCP (Mark Garrett) writes:
>
>Somebody here said they saw a film about the Lindburg flight where old
>CL was flying along, bored, and noticed a fly inside the plane.  He
>started wondering if the mass of the fly contributed to the weight
>of the plane.  If the fly is sitting on something then obviously it does.
>But what if the fly is flying around?  What if the fly is falling?  Does it
>make a difference if the plane is airtight or not?


Wether the fly is sitting on something or flying, it still contributes to the
weight of the plane, since any downward force it exerts to keep itself airborn
must eventually be comunicated to the plane. This reminds me of a similar
problem concerning an aquaduct which is just strong enough to support the weight
of water in it; if a barge sails onto the aquaduct, will it collapse?
Work it out for yourselves!
Cheers,	Dave Webb