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Re: rolling

I should stop, but how can I resist one more addendum? --Carl

SPECIAL CASE 2: heavy axle connected to two light wheels (g=0)
T = f
rotational KE = 0
translational KE = half of pseudowork you do = half of pseudowork
done by friction = real work (all done by you) - *this* is the case
where friction does half the job of translating the object

SPECIAL CASE 3: make g>1 (use a spool or connect a flywheel to the
barrel which runs through a slot in the track)
*only now* does the frictional force point backward and hence do
negative pseudowork
rotational KE > translational KE
and the pseudowork you have to do is greater than the translational
KE but less than the real work
(eg. for g=2, pseudowork done by T = 1.5K and real work = 3K)
Carl E. Mungan, Asst. Prof. of Physics 410-293-6680 (O) -3729 (F)
U.S. Naval Academy, Stop 9C, Annapolis, MD 21402-5040