Re: Weight of a Juggler

[Jack Uretsky <jlu@HEP.ANL.GOV>]

        `I Don't hink that Fourier analysis is the answwer, for the
reasons that you give.  But you seem to be able to identify fluctuations
with the approximate frequency of the juggling.  We want to subtract these
off.  This is a nice challenge; as in "real" experiments the interesting
physics lies in understanding the background "noise".
                                                Jack


On Fri, 3 Sep 2004, Folkerts, Timothy J wrote:

> Brian,
>
> Your ideas for varations sound plausible, except, I think, for the ro=
> cket.  Unless the rocket were confined to a closed box, much of the r=
> eaction force would be applied to the ground in general rather than t=
> he scale in specific, so I wouldnm't expect the force to average out =
> to the weight of the rocket.  Another similar case would be the other=
>  familiar thought experiment-
> birds flying withing a closed cage.  The weight of the cage should be=
>  the same with the birds either flying or roosting, but only if the s=
> ides are closed.
>
>
> Jack,
>
> I don't know that the more involved analysis would be effective in th=
> is case.  In principle I know where you are coming from, but in pract=
> ice I don't think the throws are consistent enough in amplitude or pe=
> riod to adequately fit any regular oscillation to the data.  The FFT =
> shows a definite peak at the frequency of the throws, but the peak is=
>  broad and lots ot frequencies besides the harmonics have noticable a=
> mplitude. =20
>
> Another option would be to find the mean weight for each period separ=
> ately, then find the mean and standard error for these numbers.  That=
>  seems much simpler and about as effective method to look for signifi=
> cant changes. =20
>
> Tim F

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