Talk:Angular frequency/Archive 1

Archive 1

Scalar or vector

Is Angular frequency a scalar quantity (= Angular speed) or a vector quantity (=Angular velocity)? If AF = scalar, then I suggest we need a new Angular velocity article regarding its vector properties and make Angular speed redirect to Angular frequency. If AF = vector, then we leave Angular velocity redirecting to Angular frequency, but need a new Angular speed article reflecting its scalar properties... ian cairns 22:05, 28 June 2004 (UTC)

Would it be appropriate to create the term "Generic frequency" by making it a numeric value of 2π times any factor of ten? This means that the frequency term that defines Angular frequency would always be a tens multiple or division of 1. Currere 22:19, 20 May 2006 (UTC)

The short answer to ian cairns is that its both. It is a scalar that forms part of a vector, because its the magnitude of the vector. However (and here's the sticking point), it shouldn't be redirected to angular velocity or angular speed (which are often confused with each other anyway, let alone with angular frequency).

The problem (speaking linearly for a moment) is that velocity is metres/second, and speed is usually the magnitude of that (because velocity is actually a vector with speed as a magnitude and a heading as direction). Cars travel at speeds of 60kph, but their velocity is technically, say, 60kph heading due west. We don't say they travelled at a frequency of 60 (units of Hertz (Hz)), because that's referring to cycles per second -- which is probably akind to saying that the car travelled west 60 times each It just doesn't make the same kind of sense.

Similar thing with circles and circular motion. Angular velocity is its speed around the circle (how fast its going round the circle). Angular frequency is how many times it can do that in a unit period of time (usually a second). Does that make sense? Or have I unknowingly tied myself up in knots at some point? ;-)

--- SahRae Hyjo 05:16, 10 September 2006 (UTC)

Angular Frequency Gif

I believe the GIF file in this entry has an error.

The quantity being calculated in the last line is labeled "v", but the value actually being calculated is frequency (f). The calculation shows cycles per second - which is frequency (f), not angular speed (v). To be consistent with the variable names in the rest of the article, the "v" in the calculation should actually be replaced with "f". The caption below the gif animation also calls frequency "v" rather than "f". Rodwishart1 (talk) 19:23, 7 December 2012 (UTC)

That's ν (nu, the greek letter), not v (v, the english letter). Nu is an extremely common symbol for frequency. (f is extremely common too.)

I acknowledge your point. On the left side of the page, there is an equation using v for velocity and f for frequency, while on the right side of the page, there is an animation using ν for frequency. This invites confusion. What to do about it?

Even if it sounds sadistic, I'm not sure it is necessarily a bad idea to use both "f" and "ν" for frequency on the same page, since they are both common in the real world and readers ought to get used to that. I put a note in the caption clarifying. I also moved v away from that part of the article. There are a number of reasons to do that, not just proximity to nu: (1) It is specific to circular motion, (2) The description is rather incomprehensible without a picture. I made it a separate section with a picture.

Does that help? Or do you think it's still a problem? --Steve (talk) 16:11, 8 December 2012 (UTC)

Misc

(1) "One revolution is 2 pi radians" might confuse some readers. It is clear to me that you mean "revolutions = radians / (2 pi)", and I would suggest "One revolution is 2 pi on the unit circle" or "radians = revolutions * 2 pi" (2) I would use capitals throughout for Henry, Farad, Hertz - they are names of people/inventors. Puddington (talk) 15:56, 17 December 2012 (UTC)

The phrase "One revolution is 2 pi radians" is in fact quite sensible. This phrase relates one unit semanticaly annotated by the idea of a rotational "revolution" to the standard unit of angular measure, the radian, by the amount "2 pi". This phrase can be rewritten as "1 revolution = 2 pi rad." which is literally a true statement. On the other hand, the phrase "revolutions = radians / (2 pi)" is in incorrect if interpreted literally. Jatosado (talk) 07:30, 24 March 2013 (UTC)