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Scott Mclean
02-21-1995, 04:21 AM
Greetings:
Sorry for the additional note but I neglected to include two
recently received responses regarding the buoyancy issue. I have appended
these to this note.

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Scott Mclean
smclean@iastate.edu

Added Responses
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Response #9

Scott:

I haven't yet seen a summary of responses to this problem. Does that mean
you've stumped the audience? Did you calculate the buoyant forces acting
on the added weights? It seems to me that your problem boils down to
seeing dB change as only the term (R2*dR2) or (R1*dR1) changes. If your
calculation of R2 were actually too high (by overestimating the added
weight), would that cause the apparent shifts you saw? Good luck!

Larry Abraham, EdD
Kinesiology & Health Education
The University of Texas at Austin
Austin, TX 78712 USA
(512)471-1273 FAX (512)471-8914

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Response #10
Scott,
Your problem has intrigued me because we all know that the equations for
equilibrium conditions must hold. The problem is to find where you have
made faulty assumptions about the equilibrium states you are comparing.
I am not clear about what you are doing with R1 and R2 and the masses
that you used to keep the pipe submerged. If you are not varying the
forces so that they remain just sufficient to maintain the identical
ploating position, your two conditions are not comparable.
The CB as you
appear to be defining it cannot change position for a solid that is of
fixed shape. What does change is what I would call the center of
floatation(or sinking). This would be the net rotational force acting on
the body when the forces R1 and R2 are altered. If I misunderstood and
you did vary R1 and R2 to be "just sufficient" then you have a mystery
that requires a very careful examination of your measurement procedures.
Please continue to keep us informed.

Leon.