Talk:Centrifugal force (rotating reference frame)

refs

Would anyone mind if I went ahead and removed the one item in "Further reading", per suggestion in last edit summary by Izno, and also convert the Taylor harv refs to the style of the rest? Do we really need the page numbers, for all these refs to the chapter "Mechanics in Noninertial Frames", or can I just say the chapter and page range? Or does someone have a better way to specify pages? Dicklyon (talk) 01:22, 12 February 2011 (UTC)

I would mind the latter suggestion only for the fact that I'm the one who switched to that style for that set. It was done with the intention of making it easier to read the references list and consolidate the text cited (do we really need the repetition of the full source information?…). Anyway, I'm not sure it's desirable to consolidate refs with such a large range of page numbers—somewhere in the range of 20 pages would make it difficult to verify the specific information in each of those sentences, though feel free to disagree… I think it might instead be more desirable to see if we can consolidate our use of references; there are currently 35 different texts and web pages cited, when this topic could and should probably be cited to 5-10 textbooks (with possible use of Harvard citation) as necessary. I'm sure that we would have plenty of texts to add to the "Further reading" section then. :^)
On a different note, do we really need so many "examples"? --Izno (talk) 03:12, 12 February 2011 (UTC)

OK, I won't mess with the refs, unless someone points out a better way to combine them in the ref style and still give page numbers. On the examples, that's the bloat I'm talking about. Brews made up and illustrated all those in his attempt to explain CF to David Tombe about two years ago. It was worse than comical; quite painful to see, and now to have to clean up, actually. Dicklyon (talk) 06:24, 12 February 2011 (UTC)

I would suggest removing the "Centrifugal couple" and the "Whirling table" sections as adding little to the discussion. We might think to merge the information in the "couple" section to Balancing of rotating masses, which looks to be a new article (which we should definitely have an article on!) and could probably use some loving or possible merging with Tire balance as the concepts in both a tire balance and the more general rotating mass balance are the same.
The "Banked turn" section is probably a good one to keep, though not in so much detail, as this is probably one of the points of confusion among the general populace. The "Dropping ball" section has an actually useful illustration which is doubled by the YouTube link in the external links section, so I think we might keep that (though it would be nice to see it cited). I think also that Earth and Planetary motion should be kept in their current condition. Thoughts? --Izno (talk) 14:30, 12 February 2011 (UTC)

Not to be confused with

There are various warnings not to confuse various forces: Centrifugal force, Reactive centrifugal force, Centripetal force, Centrifugal force (rotating reference frame). There is however no discussion of the distinction between these various phenomenon. --Kvng (talk) 20:46, 2 July 2012 (UTC)

More properly an effect than a force?

I suspect that the lead would be better if reworked à la N.M.J. Woodhouse, who writes (p. 7) in his Special Relativity (Springer-Verlag, 2003),

"In problems where the rotation matters, for example in the analysis of Foucault's pendulum, it is helpful to treat a terrestrial frame as if it were intertial, but to introduce correction terms, the 'fictitious' centrifugal and Coriolis forces, to take account of the rotation. But these are not real forces, and the frame is not really inertial."

Indeed, even Wikipedia's own article on Coriolis forces is a redirect to Coriolus effect, and that article makes it clearer than this one does that the force is only apparent. I'd have just changed it myself, but wondered if there were a good argument for retaining the nonparallelism of treating one of the two forces as though it were somehow less fictitious than the other.—PaulTanenbaum (talk) 20:57, 19 February 2013 (UTC)

My two cents here - I think there is a distinction between "effect" and "force" in these instances. My feeling from the literature that I've read is that the effect refers to the apparently anomalous deflection of the path of a particle while the force is the pseudo-force or fictitious force that is introduced to explain the deflection. As for an argument for retaining the nonparallelism, this is what we find in the literature, ie the terms "Coriolis effect" and "Coriolis force" are used with about the same frequency and sometimes it seems inter-changeably. The choice also seems to be dependent on the context - in meteorology we find "Coriolis effect" (and my guess this is true for the everyday person), while in the physics literature "Coriolis force" is more common. I don't think the same can be said for "centrifugal force"/"centrifugal effect". Just to get a general idea of how common the terms occur in the literature I searched for each phrase in google books:
• Coriolis effect : ~44,500
• Coriolis force : ~138,000
• Centrifugal effect : ~16,700
• Centrifugal force : ~1,260,000
That's almost two orders of magnitude difference for centrifugal between effect and force, while for Coriolis the two are roughly equal (okay, a factor of about 3 but less than an order of magnitude). So imo I don't care whether the other article is "Coriolis effect" or "Coriolis force", but I strongly favor keeping this one as "centrifugal force" per the usage frequency in the literature. That being said, if the intro needs to be clearer on it being a fictitious force then that should be fixed. --FyzixFighter (talk) 05:33, 20 February 2013 (UTC)
I agree with FF. If you want it more parallel, go the other way. And I'd avoid the notion of "only apparent", since we already have a well-define notion of "fictitious force" that says exactly what it is. Dicklyon (talk) 05:49, 20 February 2013 (UTC)

Acceleration Derivation

In the derivation section, I'm noticing that the last two lines of equations in the "acceleration" section do not seem to follow from one another. When I evaluate the d/dt([dr/dt]+w x r) term in the next to last line, it does not give the factor of two in front of the Coriolis term. I believe the error is leaving out part of the first derivative operator: that is, in that equation, instead of the operator "d/dt" we should have "d/dt + w x" as the operator. (also see the rotational reference frame wiki page for that derivation, in which the derivation correctly gets the factor of two into the Coriolis term) I would just go ahead and add it, except I'm not at all familiar with the proper coding for inserting equations into wikipedia, and am very new here in general — Preceding unsigned comment added by 222.221.253.76 (talk) 02:13, 6 March 2013 (UTC)

It is correct. Don't forget that
${\displaystyle {\frac {\operatorname {d} {\boldsymbol {r}}}{\operatorname {d} t}}=\left[{\frac {\operatorname {d} {\boldsymbol {r}}}{\operatorname {d} t}}\right]+{\boldsymbol {\omega }}\times {\boldsymbol {r}}\ ,}$
and of course likewise
${\displaystyle {\frac {\operatorname {d} }{\operatorname {d} t}}\left[{\frac {\operatorname {d} {\boldsymbol {r}}}{\operatorname {d} t}}\right]=\left[{\frac {\operatorname {d} ^{2}{\boldsymbol {r}}}{\operatorname {d} t^{2}}}\right]+{\boldsymbol {\omega }}\times \left[{\frac {\operatorname {d} {\boldsymbol {r}}}{\operatorname {d} t}}\right]\ ,}$
so that is where the second term comes from.
Note - this derivation could need a source. - DVdm (talk) 12:47, 6 March 2013 (UTC)