Leigh kindly gave me a second chance to improve my (A-) grade for my
solution. As John rightfully said "now back to work" - I did not have the
time to go into this problem any deeper. By now John's beautiful analyses
make such an effort totally superfluous.
I did the original problem in about 15 minutes, and therefore it was
lacking in finnesse, as Leigh pointed out. Then I spent 30 more in typing
it to Phys-l (since they never taught us how to type when I was in grade
school, and everything was done in Hebrew anyway - Leigh, that was about
the time YOU were in grade school.)
One remark though: the problem is absolutely non realistic, non physical,
non-ANYTHING, except that it is FUN. That is its intrinsic value - it makes
you think, something which I am afraid we do not emphasize enough with our
students.
Uri
Prof. Uri Ganiel
Head, Department of Science Teaching
The Weizmann Institute of Science
Rehovot 76100, ISRAEL