Date: Tue Nov 20 12:36:40 2007

Author: Van Bistrow

Subject: Re: Lifting Plate

Post:
Gary,

Yes, that is the demo I mean. I just want to scale it up a lot.

Thanks,
Van

On Nov 19, 2007, at 4:24 PM, Gary Karshner wrote:

> Van,
> This sounds like a variation of the one definite Bernoulli
> demo, I know. The others have caused great and interesting arguments
> on this list. The classic version is to stick an air hose in an old
> fashioned thread spool. Next take a piece of cardboard with a small
> nail stuck through its center and place the spool over the nail. Turn
> on the air and you can pick up the cardboard with the spool. The nail
> is only necessary to keep the cardboard from sliding horizontally off
> the spool. The air rushing past the flat end of the spool give the
> difference in pressure and you get enough lift to pickup the
> cardboard.
> I am sorry if this is not clear but I am in a bit of a rush
> today.
> Gary Karshner
>
> At 02:11 PM 11/19/2007 -0600, you wrote:
>> Thanks, Steve! Yours is the proper interpretation of my request.
>>
>> "Bernoulli" or not...
>> Imagine two flat plates, oriented with their flat surfaces horizontal.
>> One plate is centered over the other. The upper plate has a hole in
>> its center. A hose feeds air down through the hole in the upper
>> plate. The lower plate is brought up, close to the upper plate so
>> the air is forced radially outward between the two plates. There is
>> an upward force on the lower plate. I would like that upward force
>> to support a person.
>>
>> I'm sure one would need a substantial air flow to lift such a heavy
>> weight, but would like to know if anyone does this demo.
>>
>> Thanks,
>> Van
>>
>>
>> On Nov 19, 2007, at 7:50 AM, Steve Wonnell wrote:
>>
>>>
>>> Hi all,
>>>
>>> I think Van wants a different demo than what folks seem to have in
>>> mind.
>>> He's referring to the demo where air blows radially out between two
>>> plates, supporting weights ** hung from the bottom plate. *** not
>>> riding
>>> on the top plate.
>>>
>>> -- Steve
>>>
>>>
>>>
>>>
>>>
>>> On Fri, 16 Nov 2007, Van Bistrow wrote:
>>>
>>>> Date: Fri, 16 Nov 2007 11:12:46 -0600
>>>> From: Van Bistrow
>>>> Reply-To: tap-l@lists.ncsu.edu
>>>> To: tap-l@lists.ncsu.edu
>>>> Subject: [tap-l] Lifting Plate
>>>>
>>>> Dear Tappers,
>>>>
>>>> Has anyone scaled up the lifting plate demo listed below to lift a
>>>> person? What would it take to do so? What pressure? What flow
>>>> rate?
>>>> What area plates?
>>>>
>>>> 2C20.40 lifting plate Air blowing out between two horizontal
>>>> plates
>>>> supports a mass.
>>>>
>>>> Thanks!
>>>> Van
>>>>
>>>> Van Bistrow
>>>> Director, Instructional Laboratories
>>>> and Lecture Facilities
>>>> Department of Physics
>>>> University of Chicago
>>>> Phone: 773-702-7013
>>>> Fax: 773-702-7018
>> Van Bistrow
>> Director, Instructional Laboratories
>> and Lecture Facilities
>> Department of Physics
>> University of Chicago
>> Phone: 773-702-7013
>> Fax: 773-702-7018
>
>
Van Bistrow
Director, Instructional Laboratories
and Lecture Facilities
Department of Physics
University of Chicago
Phone: 773-702-7013
Fax: 773-702-7018


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