Re: Chain Problem. Was: correct answer

[Lowell Herr <herr@catseq.catlin.edu>]

Leigh,

When the end of the chain comes near the Smart Pulley, it actually leaves 
the surface of the pulley (the chain has a whip action) so the pulley 
begins to slow due to friction.  I don't want that data but rather, I 
want the data where the falling chain is showing an increasing 
acceleration.  This is why I use a program called ULI Timer and set the 
software to collect a specific number of data points.  The acceleration 
vs. time graph is 'lovely' and gives the high school student an opportunity 
to grapple with non-uniform acceleration - something they do not 
encounter all that frequently since most are just beginning calculus or 
will not get this math until college.

Lowell
> What's this about "extraneous data"? Does your chain become unphysical
> at some point? I think that the departure from the simple model can be
> an opportunity to teach something.
>
> Leigh