Talk:Cylinder/Archive 1

Archive 1

Surface area and volume of part of a sphere

I would be interested in seeing the integrals needed to find the surface area and volume of part of a sphere. This should come out of a derivation for the integrals needed to find the surface area and volume of part of a sphere. 68.6.112.70 18:26, 10 May 2006 (UTC)

Ratchets with cylindrically notched teeth

I was hoping to find some information on the mechanical properties of a ratchet with 'sawtooth' notched teeth as opposed to those having sinusoidal notches (like those that a series of cylinders would fit into). — Preceding unsigned comment added by 198.177.27.23 (talk) 03:51, 14 May 2006 (UTC)

where is z?

In the formula provided,okay $\left({\frac {x}{a}}\right)^{2}+\left({\frac {y}{b}}\right)^{2}=1$, where is the information about the height of the zylinder "hidden" (that is, where is the z-axis)? Generally, the article Cartesian equation misses to explain how to understand these equations. --Abdull 07:52, 29 May 2006 (UTC)

• It means that z can be anything. The equation describes the surface of an infinitely long cylinder around the z-axis CuriousOliver 19:50, 17 July 2006 (UTC)

Is this the geometric cylinder?

Correct me if I'm wrong, but this doesn't seem to talk much about the cylinder as a solid; instead it seems to look mostly at the cylinder as a Cartesian equation, which is more mathematical than anything else (or at least to me). Does anyone else agree? --JB Adder | Talk 01:06, August 4, 2005 (UTC)

I agree, this page isn't very complete. You can help! 68.6.112.70 18:26, 10 May 2006 (UTC)

This one may not cylinder in geometry commons, this is only cylinder (quadric). How about the extended concept? Newone 06:32, 16 September 2007 (UTC)

strength

hello, i was wondering how strong a cylinder can be? if possible contact meon mye-mail adress

thank you — Preceding unsigned comment added by 65.94.55.246 (talk • contribs) 00:32, 10 April 2005 (UTC)

Its not a good idea to put your email up here, so I removed it. 68.6.112.70 18:26, 10 May 2006 (UTC)

If you want us to contact you, allow email from other Wikipedians and sign your posts like this- ~~~~. Lunakeet 12:12, 9 May 2008 (UTC)

finding out the volume of a cylinder with un equal radius

finding out the volume of a cylinder with un equal radius —Preceding unsigned comment added by 117.192.165.48 (talk) 18:47, 20 April 2010 (UTC)

What is the volume of a section, when a plane intersect the cylinder through the bases, along his length? —Preceding unsigned comment added by 188.131.71.205 (talk) 15:15, 21 July 2010 (UTC) hi i want to know how to calculate the volume of a cylinder. i do not understand the given formula contact me @ www.moshimonsters.com/zeduleika —Preceding unsigned comment added by 173.35.224.172 (talk) 02:12, 4 November 2010 (UTC)

typo?

Hi, are you sure

   =\int_{0}^{h} A(y)^2 \, dy

is right, shouldn't it be

   =\int_{0}^{h} A(y) \, dy

without the square? — Preceding unsigned comment added by 193.174.18.152 (talk) 08:46, 30 June 2011 (UTC)

Pi

So, no one else has noticed that all the equations are missing pi. Is there any reason for this? — Preceding unsigned comment added by 216.200.101.146 (talk) 19:34, 10 February 2012 (UTC)

Difference among cylinder, circular cylinder, and right circular cylinder?

Can anyone explain the difference among cylinder, circular cylinder, and right circular cylinder? I believe it can enhance the article.--Gqqnb (talk) 13:29, 5 June 2012 (UTC)

Definition

The first sentences are problematic:

A cylinder ... is one of the most basic curvilinear geometric shapes, the surface formed by the points at a fixed distance from a given line segment, the axis of the cylinder. The solid enclosed by this surface and by two planes perpendicular to the axis is also called a cylinder.

Contrary to what the above text says, the surface formed by the points at a fixed distance from a given line segment is usually denoted a sphero-cylinder (made of two half-sphere surfaces) which is not usually considered a cylinder.78.240.176.157 (talk) 13:02, 18 August 2015 (UTC)

Formally, you are right: one only gets an (infinite) cylinder by considering points equidistant of its axis, which is a line, rather than a line segment. So there is an easy fix. However, this does not completely solve the problem. Pedagogically, I would be disinclined to make the lead too precise — after all, in common use, coming from school geometry, a cylinder is a familiar finite shape (inluing the flat "caps"), whereas from the more advanced point of view, many variants are also called "cylinder", with the main one being the infinite right circular cylinder. Perhaps, you have an idea how to handle this tricky issue in the body of the article? This would also address the request above to explain the differences between various uses of the term "cylinder". Arcfrk (talk) 06:53, 20 August 2015 (UTC)

I think that "curvilinear" and the remark that the cylinder is a basic shape should not be in the first sentence. Rather, we should acknowledge that the word "cylinder" has a variety of different meanings and describe them in several sentences. In general, when the "cylinder" term is used without other precision, it means the right circular cylinder. For right cylinders, the term "cylinder with <some shape> cross-section" is used with <some shape> being triangle, square etc. A non-right cylinder is usually refered to as a generalized cylinder. As always, Wolfram has some good introduction, which we can follow somehow http://mathworld.wolfram.com/Cylinder.html 195.83.117.137 (talk) 13:58, 21 August 2015 (UTC)

Adding a helpful online program to the link list?

Hello everyone, since this is my first edit to the Wikipedia I would like to know if I can add a helpful link to the main page of this article under "External Links". The link is for an online program: Cylinder Calculation 3D - there you specify two values only and all the other values get calculated automatically, plus you have an interactive 3D visualization of the resulting 3d cylinder, and some nice graphics. Thank you in advance Matheretter (talk) 11:15, 31 August 2015 (UTC)

I think online calculators make bad external links. In any case, can you explain why you think it passes WP:ELNO? —David Eppstein (talk) 15:45, 31 August 2015 (UTC)

Hi David and thanks for your reply. I have checked all the points from your link and do not see why the provided link should not be suitable. https://en.wikipedia.org/wiki/Wikipedia:External_links#What_can_normally_be_linked says that "Sites that contain neutral and accurate material that is relevant to an encyclopedic understanding of the subject". I would say the linked program helps understanding cylinders essentially better since you can interact in 3d with them, plus when you set the values of the cylinder it changes its shape accordingly and calculates all others, so a big help for students and teachers. But this is my POV. That's why I asked here on this talk page. Matheretter (talk) 16:34, 31 August 2015 (UTC)