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written by Mario Belloni
This model displays the statics and dynamics of a ladder leaning against a wall. The standard (textbook) statement of this problem assumes that there is no frictional force between the wall and the ladder, but a frictional force between the ground and the ladder. In the simulation, students set the initial lean angle and the coefficients of static and kinetic friction between the floor and the ladder. This resource includes background information and related problems.

Editor's Note: In teaching about equilibrium, instructors may want to use "bite-size" pieces to slowly build concepts. This simulation presents the concept with very simple graphics, appropriate for the introductory class. See Related Materials for a more complex simulation that introduces a person standing on the ladder.

This item was created with Easy Java Simulations (EJS), a modeling tool that allows users without formal programming experience to generate computer models and simulations. To run the simulation, simply click the Java Archive file below. To modify or customize the model, see related materials for installing and running the EJS Modeling and Authoring Tool.

Please note that this resource requires at least version 1.5 of Java (JRE).
View the source code document attached to this resource
Subjects Levels Resource Types
Classical Mechanics
- Newton's Second Law
= Force, Acceleration
- Statics of Rigid Bodies
= Equilibrium
- High School
- Lower Undergraduate
- Instructional Material
= Activity
= Curriculum support
= Interactive Simulation
= Lecture/Presentation
Appropriate Courses Categories Ratings
- Conceptual Physics
- Algebra-based Physics
- AP Physics
- Activity
- New teachers
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Access Rights:
Free access
© 2008 Mario Belloni
Additional information is available.
Easy Java Simulations, Ejs, OSP, Open Source Physics, ladder, ladder demo, ladder problem, statics, tpt ladder
Record Creator:
Metadata instance created August 17, 2008 by Mario Belloni
Record Updated:
June 5, 2014 by Andreu Glasmann
Last Update
when Cataloged:
August 18, 2008
Other Collections:


Author: Michael Grams
Posted: December 2, 2009 at 3:48PM
Source: The Open Source Physics collection

The ladder falls for any value of theta and any value of the coefficient of static friction.  What am I missing?

» reply

Re: Confusion

Author: Michael Grams
Posted: Dec 02, 2009 at 3:55PM

> On Dec 02, 2009, Michael Grams posted:
> The ladder
> falls for any value of theta and any value of the
> coefficient of static friction.  What am I missing?

Nevermind, I realized what the problem was.  You have to hit enter after putting in your values of theta and mu.

» reply

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AAAS Benchmark Alignments (2008 Version)

4. The Physical Setting

4F. Motion
  • 9-12: 4F/H4. Whenever one thing exerts a force on another, an equal amount of force is exerted back on it.
  • 9-12: 4F/H7. In most familiar situations, frictional forces complicate the description of motion, although the basic principles still apply.

11. Common Themes

11B. Models
  • 6-8: 11B/M4. Simulations are often useful in modeling events and processes.
  • 9-12: 11B/H3. The usefulness of a model can be tested by comparing its predictions to actual observations in the real world. But a close match does not necessarily mean that other models would not work equally well or better.
ComPADRE is beta testing Citation Styles!

Record Link
AIP Format
M. Belloni, Computer Program EJS TPT LADDER DEMONSTRATION MODEL, Version 1.0 (2008), WWW Document, (http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635).
M. Belloni, Computer Program EJS TPT LADDER DEMONSTRATION MODEL, Version 1.0 (2008), <http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635>.
APA Format
Belloni, M. (2008). Ejs TPT Ladder Demonstration Model (Version 1.0) [Computer software]. Retrieved July 30, 2014, from http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635
Chicago Format
Belloni, Mario. "Ejs TPT Ladder Demonstration Model." Version 1.0. http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635 (accessed 30 July 2014).
MLA Format
Belloni, Mario. Ejs TPT Ladder Demonstration Model. Vers. 1.0. Computer software. 2008. Java (JRE) 1.5. 30 July 2014 <http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635>.
BibTeX Export Format
@misc{ Author = "Mario Belloni", Title = {Ejs TPT Ladder Demonstration Model}, Month = {August}, Year = {2008} }
Refer Export Format

%A Mario Belloni
%T Ejs TPT Ladder Demonstration Model
%D August 18, 2008
%U http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635
%O 1.0
%O application/java

EndNote Export Format

%0 Computer Program
%A Belloni, Mario
%D August 18, 2008
%T Ejs TPT Ladder Demonstration Model
%7 1.0
%8 August 18, 2008
%U http://www.compadre.org/Repository/document/ServeFile.cfm?ID=7849&DocID=635

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Citation Source Information

The AIP Style presented is based on information from the AIP Style Manual.

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Ejs TPT Ladder Demonstration Model:

Same topic as LTU Physlet: Ladder Leaning Against a Wall

This is a related, but somewhat more complex Physlet which introduces an additional force: a person standing on the leaning ladder.

relation by Caroline Hall
Is Based On Easy Java Simulations Modeling and Authoring Tool

A link to the free Easy Java Simulations Modeling and Authoring tool, which is needed to modify the computational model used in the Ladder Demonstration model.

relation by Caroline Hall

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