Re: When Physical Intuition Fails

[Gary Turner <turner@MORNINGSIDE.EDU>]

> > There's an interesting linear problem that addresses the same issue.
> > Drop a package onto a moving conveyor belt. The package will slip
> > (and accelerate) until it reaches the speed of the belt - thereafter
> > it moves at the speed of the belt.
>
> This problem doesn't address the same issue.  There is work done (oh
> dear!) on the box, no interplay between angular and linear momentum,
> and the final speed is obvious.


***POSSIBLE SPOILER***
That's how I started - with a work-energy relation.  Then realized that
I was out information - the "distance" finished up inversely proportional
to mu.  That lead to 1-D motion, with accel*distance prop to delta-v^2, so
long as the acceleration is constant - which it is, because it is caused by
kinetic friction. (assuming, of course that we are not burning rubber on
this wheel!)
That sort of implied mu independence for the final answer  (about 10
minutes wasted here)

But then I tried just the basic v=v_0+at for linear and angular
velocities.  The answer drops out in a couple of lines.  Is there anything
wrong with using this method?

Is the answer mu independent?
> --
> John Mallinckrodt        mailto:ajm@csupomona.edu
> Cal Poly Pomona          http://www.csupomona.edu/~ajm
>
> This posting is the position of the writer, not that of SUNY-BSC, NAU or
the AAPT.

This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.