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Re: Need Doppler Demo (fwd)

I have used the buzzer and nerf ball for a couble of years and while I
still use it it has some draw backs.

1. The buzzeer is directional, and if the ball has any rotation when
it is thrown there is a noticable pulse in both volume and dopler shift.
If you can "put" it like a shot put or throw a great knuckle ball it
helps.

2. If you tie it to the end of a long string and swing it around
your head you can minamize the rotational wobble but there is a
significant variation in volume that we all know accompanies dopler
shift. After some indepth discussions with students in subsiquent master
confrences the majority of my students identified the volume change
rather than the change in pitch as the primary dopler effect.

I would be very intrested in any thing that works better. I was
fortunate that my school was on a 8 lane loop (IH635) around Dallas and
we could go out and listen to the cars.

On 13 Aug 1996, Brad Shue wrote:


Buy a piezo buzzer from the shack, hook it up to a battery using 3 or 4
feet of wire. Use the wire as a tether and swing it around over your head
with the buzzer running.

--
James Bradford Shue jshue@comp.uark.edu
University of Arkansas Voice phone:(501) 575-6059
Physics Lab/Demo Curator FAX Number: (501) 575-4580
WWW Page http://comp.uark.edu/~jshue



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