Talk:Centripetal force

Section 'Local Coordinates'

Caught my eye as I was browsing. Reference number 23 is from a book that I'm currently studying. It may be somewhat trivial, but this book has little to nothing to do with physics or local coordinates or centripetal force. If you were to look at the book mentioned, you would indeed find a mention of local coordinate systems, but not at all in the context of physics or centripetal force. The book is a treatise on a particular method for numerically solving differential equations. It should not be hard to come up with a better reference for this definition of Local coordinates — Preceding unsigned comment added by 124.148.162.180 (talk) 14:45, 14 March 2012 (UTC)

Constant Speed?

The speed of the object is constant only if the orbit is circular. For an elliptic orbit, the *area* swept out p.u. time is constant, but the speed is not. The total angular momentum remains constant since the center body cannot exert a torque on the system. This implies the equal swept area principle, first derived by Newton. The article also needs to cover the usual arguments between centripetal v. centrifugal forces and accels.220.244.84.179 (talk) 23:19, 27 May 2013 (UTC)

What expression has the elliptical case?--5.15.37.20 (talk) 12:59, 14 February 2014 (UTC)

Inverse square law for relativistic centripetal force

The speed in the formula is squared, so twice the speed needs four times the force. The inverse relationship with the radius of curvature shows that half the radial distance requires twice the force. (However if angular momentum is conserved then halving the radial distance will double the velocity and therefore the centripetal force will be eight times as great). This force is also sometimes written in terms of the angular velocity ω of the object about the center of the circle, related to the tangential velocity by the formula

In particle accelerators, velocity can be very high (close to the speed of light in vacuum) so the same rest mass now exerts greater inertia (relativistic mass) thereby requiring greater force for the same centripetal acceleration, so the equation becomes:

$F={\frac {\gamma mv^{2}}{r}}$

where

$\gamma ={\frac {1}{\sqrt {1-v^{2}/c^{2}}}}$

is called the Lorentz factor. (If the velocity is very close to the speed of light and if angular momentum is conserved then halving the radial distance will have very little effect on the velocity but will approximately double the value of the Lorentz factor and therefore the centripetal force will be approximately four times as great)

Just granpa (talk) 17:59, 29 June 2016 (UTC)

Wikipedia needs reliable sources—see wp:RS. Without sources, this is called original research and not allowed—see wp:NOR. That is why I removed it from the article ([1]). Without such sources, you are actually not discussing the article here, but part of the subject, which is also not allowed—see wp:TPG. Yes, Wikipedia has many and tough rules. - DVdm (talk) 18:10, 29 June 2016 (UTC)

New figure

Uses vector subtraction and similar triangles to get a=v^2/R

In an article with more than enough figures establishing the law for uniform circular motion, I don't see how this fits in. But this is FYI for editors who contribute to other wikis or other pages on WV.--Guy vandegrift (talk) 18:05, 28 February 2020 (UTC)

External links

There are nine entries in the "External links". Three seems to be an acceptable number and of course, everyone has their favorite to add for four. The problem is that none is needed for article promotion.

• ELpoints #3) states: Links in the "External links" section should be kept to a minimum. A lack of external links or a small number of external links is not a reason to add external links.
• LINKFARM states: There is nothing wrong with adding one or more useful content-relevant links to the external links section of an article; however, excessive lists can dwarf articles and detract from the purpose of Wikipedia. On articles about topics with many fansites, for example, including a link to one major fansite may be appropriate.
• WP:ELMIN: Minimize the number of links. -- Otr500 (talk) 12:18, 27 February 2023 (UTC)