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ERIC Number: EJ926934
Record Type: Journal
Publication Date: 2011-May
Pages: 2
Abstractor: As Provided
Reference Count: 5
ISBN: N/A
ISSN: ISSN-0031-921X
Revisiting the Ladder on a Wall Problem
Salu, Yehuda
Physics Teacher, v49 n5 p289-290 May 2011
The problem of a ladder leaning on a wall has been a staple of introductory physics for years. It is discussed in numerous physics textbooks and in journals. Now, it even has an Internet presence. Postings from students seek help for "ladder on a wall" problems. A quick review of those postings would show that they all deal with frictionless walls. This is also how the situation is presented in most textbooks. One may get the impression that the friction between a ladder and a wall is always negligible, or that dealing with it is so difficult that it should be left out of the realm of introductory physics. The truth of the matter is that the magnitude of the friction coefficient between a ladder and a wall is not much different from that with the floor, and that friction with the wall is an important part of the conditions for having a static ladder. This paper derives a simple relationship between the friction coefficients of the ladder with the floor ([mu][subscript 1]) and with the wall ([mu][subscript 2]), when the ladder is in static equilibrium. Figure 1 shows the forces that act on a ladder that leans on a wall.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail: pubs@aapt.org; Web site: http://scitation.aip.org/tpt
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A