I. If the block(on the small side) moves down the table
without being given a start, it is probably
being accelerated when it does get started.
II. Most pieces of lumber are not the same on two adjacent
sides -- different side of the grain showing;
different number of fingerprints; different
flatness; etc.
III.Sometimes the empirical laws of friction just don't
work. It is interesting that they work as
frequently as they do since we really have no
compelling reason to suspect that they would.
In summary, friction problems are a fascinating AND
frustrating problem if you are going to get it right in the
real world. WBN
Barlow Newbolt
Department of Physics and Engineering
Washington and Lee University
Lexington, VA 24450
There is something fascinating about science. One
gets such wholesale returns of conjecture out of
such trifling investments of fact.
Mark Twain
Telephone and Phone Mail: 540-463-8881
Fax: 540-463-8884
e-mail: NewboltW@madison.acad.wlu.edu