Talk:Inclined plane

Usefulness

Bold text How are inclined planes useful? — Preceding unsigned comment added by 205.204.242.21 (talk) 17:19, 30 August 2004 (UTC)

From the article:

"The inclined plane is used to reduce the force necessary to overcome the force of gravity when elevating or lowering a heavy object. The ramp makes it easier to move a physical body vertically by extending the distance traveled horizontally (run) to achieve the desired elevation change (rise)."

=> This means that if you are not strong enough to lift an object straight up, you can overcome this with a ramp; with a ramp you can lift the object using a smaller force, at the cost of having to lift it a longer distance. I think this article needs some language and explanatory cleanup. Do you think this should be better explained in the article? [[User:Sverdrup|❝Sverdrup❞]] 17:35, 30 Aug 2004 (UTC)

Example problem

I've started cleaning up the example physics problem. I don't have time to do it all now, but I think it needs to be tightened up significantly. flowersofnight (talk) 20:56, 14 June 2006 (UTC)

Audio Recording

(edited)I changed my mind, re-reading this it seems like it needs some more work...It looks like the inclined plane and the wedge have been confused (not that they are all that different anyway).

--Freeflight 08:08, 1 November 2006 (UTC)

No cites, or copy+pasting

This entire article has been copied and pasted from this site: http://www.weirdrichard.com/inclined.htm

Surely someone had just pasted it on without citing it... —The preceding unsigned comment was added by 74.116.163.147 (talk) 22:06, 18 March 2007 (UTC).

Well I think that site should be fined!! Don't you?

jessica lamond203.214.128.97 (talk) 09:04, 5 March 2008 (UTC)i'm a wierd person!!

[incorrect mechanical advantage statement]

before I changed it, the article read that the IMA of an inclined plane can also be expressed as the sine of the angle between the slope and horizontal plane. This is wrong, because the IMA is the hypoteneuse over the height, not the other way around.

I have changed it to read the ratio of 1 to the sine of that angle described above to make it correct — Preceding unsigned comment added by 99.141.23.37 (talk) 15:34, 14 February 2008 (UTC)

Energy expenditure

"Many devices based on the principle of the inclined plane allow expending less individual energy to achieve a task."

I believe this is incorrect. At best, an inclinded plane requires expending exactly the same amount of energy when used to increase the elevation of a weight, hence the expression $\,\Delta PE=mg\Delta h$. In reality, where loss due to some sort of friction is unavoidable, an inclinded plane may actually require more energy to raise a weight than simply lifting it outright. -AndrewDressel (talk) 13:55, 21 May 2008 (UTC)

Merge with Wedge

This entire article needs to be merged with the Wedge article. An inclined plane is nothing but a stationary wedge. Calling the same machine element by two separate names leaves a distinctly confusing impression on readers. Brittanica drops any references to inclined planes in all of its articles, so should Wiki. WittyMan1986. —Preceding unsigned comment added by 71.22.158.60 (talk) 21:14, 12 March 2010 (UTC)

Photo from Masada

The example photo from Masada is almost entirely useless. Unless you're familiar with Masada it is impossible to recognize what is being portrayed.

Surely there is a better photo that can be used?? —Preceding unsigned comment added by 174.148.148.187 (talk) 12:42, 1 July 2010 (UTC)

By all means, please provide a replacement. -AndrewDressel (talk) 14:16, 1 July 2010 (UTC)

Picture really needs a replacement 207.163.165.5 (talk) 19:35, 8 June 2011 (UTC)

Revisions to inclined plane

This article is linked to the article on simple machines which is used by elementary school teachers to introduce technology. I would like to make some revisions that maintain its historical foundation but streamline the presentation consistent with modern machine theory. Prof McCarthy (talk) 16:28, 13 December 2011 (UTC)

Colleagues, thank you for your patience with these revisions. I deleted material that discussed chutes and airfoils that are curved surfaces and not inclined planes. I moved the material on wedges and blades to the article on wedges. Finally, I rewrote the derivation of mechanical advantage. I realize that work is generally used rather than power, but I do not think this is more complicated and it matches current machine theory more closely. Prof McCarthy (talk) 16:07, 14 December 2011 (UTC)

Which comes first...

I guess I understand the desire to rewrite the description of an inclined plane in what seems to be a more precise though abstract form. If one understands how a "flat surface" can lie at an angle with level ground, then they will probably understand that this it is the same as "a straight ramp that is cut into a hillside and used for moving loads up and down the hill." On the other hand, the physical realization of the inclined plane as an important tool for transportation motivates both the analysis of mechanical advantage and the abstraction to planes, angles and level ground. While some prefer explanations that move from abstraction to realization, I believe it makes more sense to move from realization to abstraction. However, I will leave the revisions to this article alone. In addition, "funicular" refers to a particular means for powering movement on an inclined plane which is by cable, and also refers to cars suspend on cables. Therefore, it is somewhat imprecise to consider funicular as an alternative expression for inclined plane. Prof McCarthy (talk) 06:40, 16 April 2012 (UTC)

I don't know if it is more precise, it certainly is more abstract, but I believe its main advantage is that it is more general and covers more implementations, such as wheelchair ramps. Yes, readers will have to be able distinguish "flat" from "level". As for whether it is better to start with a specific example or a general definition, I believe the convention for encyclopedias, which we are trying to write, is to start with a general definition.

It seems that mechanical inclined planes encompass cable railways, cog railways, and funiculars. The cable railway article specifies that "a specific type of cable railway is the funicular, which is a cable railway with the cars permanently fixed to the cable.[2] Usually funiculars are self-contained and not connected to other railway networks," with a print reference in German. Would you agree? -AndrewDressel (talk) 16:10, 16 April 2012 (UTC)

I agree. Thank you for the revisions to the article. By the way inclined plane as a ramp in a hillside is not just a railroad, but also can be one of a systems of ramps used to move boats between waterways. Prof McCarthy (talk) 23:36, 16 April 2012 (UTC)

Rewrite

I rewrote and expanded the article. Here are reasons for some changes I made to the existing content:

• The existing introduction didn't comply with WP:LEAD as an overview of the contents of the article. It needed more description of the mechanics, particularly the notable fact that the inclined plane doesn't change the amount of work done in raising an object
• The "Mechanical advantage" section used power and velocity, rather than the usual force and distance, to derive the mechanical advantage. While this might have some advantages for advanced readers, this is a general purpose encyclopedia, so I changed it to the more familiar approach. The power,velocity approach is less visual, and the usual vocabulary of force, distance, and work concepts is more familiar to less technically-educated readers, and demonstrates the analogy with other simple machines. I've looked at dozens of expositions of the inclined plane in textbooks and websites, and none of them use the power approach, probably for the above reasons. There will be a lot of kids coming to this article for their homework; and I feel we need to use the clearest, most understandable derivations.

--Chetvorno^TALK 08:09, 9 September 2012 (UTC)

I added the section using power to compute mechanical advantage at the end for more advanced readers who recognize that the computation of work is path dependent. These readers will find that the calculation of work requires assumptions that can get in the way of understanding the relatively simple property of mechanical advantage. I recognize that most presentations at a elementary level focus on work, but this requires the assumption of constant force maintained over the length of the ramp which is contrary to the experience of anyone who uses a ramp. While velocity may not be a familiar concept, it is my opinion that those who are aware of this contradiction will appreciate and value the central role of power and velocity. Prof McCarthy (talk) 20:22, 9 September 2012 (UTC)

I understand; also that approach allows curved ramps to be treated. I have no objection as long as the work/distance derivation is also included for nontechnical readers. Perhaps the advantages and wider applications of the power method could be mentioned in the section lead, to give a rationale for the separate derivation? And the section should be sourced. --Chetvorno^TALK 09:33, 10 September 2012 (UTC)

It would also be nice to unify the variable names throughout the article. The weight of the load, W in the power section, I called F_w in the force/distance derivation, because W is used for work. And the applied force, F in the power section, is F_i in the other derivation. Would you be willing to change those variables in the power derivation? --Chetvorno^TALK 10:12, 10 September 2012 (UTC)

Yes. Prof McCarthy (talk) 15:21, 10 September 2012 (UTC)

Recent additions to Stevin's proof

Do you have another source besides the (inaccessible) Dijksterhuis reference? I haven't seen these criticisms before in any other sources. --Chetvorno^TALK 17:28, 8 September 2013 (UTC)

I don't really see that it's true, as Shanker Pur's addition claims, that the the hanging portion of the chain can only be symmetrical if the planes have the form of an isosceles triangle. Look at Stevin's illustration at the top of the box. The hanging beads are symmetrical even though the inclined planes are not. In fact any issues about the locations of the beads on the chain can be reduced to negligible by shrinking the beads and locating them closer together, until the chain approximates a continuous string with a constant weight per unit distance along its length. It seems to me that this limiting argument was clearly in Stevin's mind, and is inherent in his proof. --Chetvorno^TALK 16:29, 9 September 2013 (UTC)

I'll try again. I don't see what the shape of the two inclined planes (isosceles or not) has to do with the forces exerted on the ends of the chain by the catenary portion of the chain hanging entirely below the planes. As long as the beads are located symmetrically, the two forces exerted on the ends of the chain by the free hanging portion will be equal. --Chetvorno^TALK 21:16, 14 September 2013 (UTC)

Inclined plane with friction

I find this section to be unsatisfactory. "Applied force" (Fi) is poorly defined. Is it a component of gravity or an external force? Then we have the graphic on the right which does not show Fi, and does not explicitly mention "Applied force". Please clean this up, somebody. Asgrrr (talk) 21:49, 19 July 2016 (UTC)

I wrote this section. The forces are defined in the bullet points to the left: "The applied force, Fi exerted on the load to move it, which acts parallel to the inclined plane." In other words, the external force. I agree, it's not as clear as it should be. About the diagram, I couldn't find one that uses f_i and I didn't want to change the terminology used throughout the article. The definitions of the variables in the diagram are given in the caption. --Chetvorno^TALK 08:22, 20 July 2016 (UTC)

Replacement of Force Diagram

• 
  Free body.svg (current version)
• Free body1.1.svg
  Free body1.1.svg
• Free body1.2.svg
  Free body1.2.svg
• 
  Free body1.3.svg

All three "upgrades" are superior to the current version, and were created by one of my students at my suggestion (as part of a course requirement to improve the teaching materials). Since it is on so many wikis, I have sought council from Commons regarding how to replace. You are welcome to comment at c:File talk:Free body.svg.--Guy vandegrift (talk) 16:42, 27 January 2017 (UTC)

I can only see some small cosmetic difference between the current version and the three new ones. None of them are correct free body diagrams. -AndrewDressel (talk) 14:33, 3 February 2017 (UTC)

The problem with the figure in the current article is that the number of forces is confusing. First year physics students have difficulty recognizing that ma is not a force (is needs to be called a pseudoforce). The image in the article represents gravity (weight) and its two components as equivalent forces. The dotted line allows the instructor identify that weight is broken into two components. When summing all the forces, one either includes weight, or the two perpeniduclar components of weight, but not all three. In a related vein, friction and the normal force can be combined into a single force called the contact force. While these may be simple ideas for the already-trained mind, trust me when I tell you that college students have great difficulty here.

Since you consider the changes cosmetic, I presume you won't mind us making the substitution, right? Also, I just noticed that the same figure appears later in the diagram, which is strange for a wikipedia article. I won't touch the second image till consensus is reached (or at least implied by silence)--Guy vandegrift (talk) 16:41, 5 February 2017 (UTC)

Exploring the World of Physics

This source by Tiner is published by New Leaf Publishing of the Institute for Creation Research that publishes miscellaneous topic books incorporating evolution-denial and pseudoscience about the age of the Earth, etc. These should be considered unreliable sources, with exceptions depending on circumstances. This particular source is not the worst I've seen and is still a basic textbook authored by a teacher. Considering this and that it's being used more than once in the article, is not refspam, I'll leave it for this article. I still wanted to let interested editors know that sources on the topic by more reputable publishers are easy to find and could potentially replace it. While I only have access to what Google Books allows, a few basic searches did turn out various Bible reading encouragements, then a bogus foreknowledge claim at p. 4, but no apparent evolution denial. Thanks, —PaleoNeonate – 22:24, 19 January 2020 (UTC)

@PaleoNeonate: Removed the Tiner citations. I might have been the one that added that source; thank you very much for catching that! As you say, there are plenty of reliable sources for these subjects. Cheers --Chetvorno^TALK 23:38, 19 January 2020 (UTC)

If that's the case, it's a reminder of how easy it is to mistake these for reliable sources (still, this one seems exceptional in quality compared to some others I've recently evaluated and removed from articles). Thanks again, —PaleoNeonate – 01:19, 20 January 2020 (UTC)

Citation doesn't back up claim

In the "Uses" section, it is stated that "Inclined planes are widely used in the form of loading ramps to load and unload goods on trucks, ships and planes." with a citation to Math and science activity center. Edinformatics. 1999. A readthrough and search of the source fails to find a statement that backs up this claim, however. Is it appropriate to remove the citation for this statement? — Fredrick Campbell (talk) 07:25, 9 May 2022 (UTC)

I wrote most of that section. You’re right, it doesn’t support that statement and should be removed. Good catch. --Chetvorno^TALK 20:33, 9 May 2022 (UTC)