Date: Thu, 3 Jun 2004 14:50:49 -0400

Author: Wolfgang Rueckner

Subject: Re: buoyancy

Post:

Of course. I guess all my sparkplugs weren't firing. Thanks -- Wolfgang


>....But the less dense part (the wood) of the wood-water mix is moving
>upward, so the center of mass of the wood-in-water system is moving
>downward.
>
>DickBerg
>
>On Thu, 3 Jun 2004, Wolfgang Rueckner wrote:
>
>> >At 08:28 AM 6/3/2004, you wrote:
>> >>>... Someone suggested that the key to understanding this
>> >>>experiment is to realize that the center of mass of the system is
>> >>>falling when the wood block is rising.
>> >>
>> >>When the wood block is rising, isn't the center-of-mass rising?
>> >
>> > What is your reasoning? The way I initially thought of it (and
>> >somebody else pointed this out) was to think about where the water
>> >level is before and after. Or imagine replacing the block of wood
>> >at the bottom with a block of water the same size...
>>
>> My reasoning hinges on the phrase "when the wood block is rising" --
>> the water level doesn't change while it's rising. Granted, once it
>> breaks the surface the level changes, but I thought your measurements
>> recorded while the block was still submerged. -- Wolfgang
>>
>>
>
>***********************************************************************
>Dr. Richard E. Berg, Professor of the Practice
>Director, Physics Lecture-Demonstration Facility
>U.S. mail address:
>Department of Physics
>University of Maryland
>College Park, MD 20742-4111
>Phone: (301) 405-5994
>FAX: (301) 314-9525
>e-mail reberg@physics.umd.edu
>www.physics.umd.edu/lecdem
>***********************************************************************
From dimarco@physics.montana.edu Thu Jun 3 14:48:35 2004

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