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



Still not posted, but there’s now posted the data from the “UFO” spinner. I glued a paper tab on the edge of the UFO, so only one “lobe”. Used time 1. i.e. time is one rev. The last column is the interuppted time.

bc relaxing in the Bru house w/ a pumkin spice laté in Ataskadero on way to SBHS reunion (Santa Barbara).



On 2017/Sep/21, at 11:34, bernard cleyet <bernard@cleyet.org> wrote:


On 2017/Sep/21, at 10:30, John Denker via Phys-l <phys-l@mail.phys-l.org> wrote:


BC spinner #1 has a loose bearing. This is observed explicitly,
and also implicitly at the high-speed end of the recorded data,
where the data is very messy, which can be explained by wobble
and shimmy. Furthermore, over most of the range the friction
is dominated by a zeroth-order term, more-or-less in accordance
with Coulomb's law of sliding friction


All of them (my four) wiggle.

Evidently I haven’t posted my graphs. IIRC, (I’m 80 and was concussed by a mugger), My conclusion is mostly lin. and quad. not much da Vinci dissipation.


https://phys.org/news/2016-05-leonardo-da-vincithe-systematic-friction.html




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