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Re: [Phys-L] fidget spinner: more data, more analysis, timestamps, force-law plot




On 2017/Sep/21, at 09:45, David Bowman <David_Bowman@georgetowncollege.edu> wrote:

Both of these hypotheses are testable. BC's photos show he has both an axially symmetric and a lobed spinner whose spin-down data can be contrasted. Also, if a spinner shows a constant drag force term perhaps a tiny drop of very light lubricating oil on the bearings may make that contribution greatly reduced, if it is indeed caused by a dry kinetic friction mechanism.

David Bowman
______________

OK, next project, I pray, to attach a flag to the UFO spinner.

Note a problem in the very diff. moments of inertia.

bc, prays often.


p.s. when I can dig up a widely spaced PG, I’ll collect the run down of one of our ceiling fans — rather long to decay despite being a fan!, as they’re well bearing’d, and large MOI. And may try both cleaning and lubing a bearing.