1K10.20 - Ladder Forces

See first paragraph in procedure
See second paragraph in procedure.
Code Number:
Demo Title:
Ladder Forces
Components of Forces
Area of Study:
Ladder with Rollers on one end, slotted weights and hanger.

Stand the ladder against a wall with the wheels on the wall. Weights may be hung on the various rungs of the ladder to where the ladder starts to slip when set at different angles.  

An interesting version is to make both ends of the ladder frictionless.  When the ladder starts to slide, the top end of the ladder leaves the wall at some point or rotates away from the wall, due to the bottom of the ladder rapidly moving away from the wall. 

  • Daniel Kaplan, "Observing the Forces Involved in Static Friction Under Static Situations",  TPT, Vol. 51, # 4, April 2013, p. 224.
  • Jonathan Bennett, Alex Mauney, "The Static Ladder Problem with Two Sources of Friction", TPT, Vol. 49, # 9, Dec. 2011, p. 567.
  • Yehuda Salu, "Revisiting the Ladder on a Wall Problem", TPT, Vol. 49, # 5, May 2011, p. 289.
  • Mario Belloni, "A Simple Demonstration for the Static Ladder Problem", TPT, Vol. 46, # 8, Nov. 2008, p. 503.
  • Joe Meyer, "Ladder Physics", TPT, Vol. 26, # 8, Nov. 1988, p. 532.
  • Thomas J. Parmley, J. Irvin Swigart and Ray L. Doran, "Lecture Demonstrations for the High School Science Teacher", TPT, Vol. 4, # 1, Jan. 1966, p. 36.
  • "Problem That Bother Me", TPT, Vol. 4, # 3, March 1966, p. 144. 
  • Alejandro G. Gonzalez and Julio Gratton, "Reaction Forces on a Ladder Leaning on a Rough Wall", AJP, Vol. 64, #8, Aug. 1996, p. 1001.
  • Kenneth S. Mendelson, "Statics of a Ladder Leaning Against a Rough Wall", AJP, Vol. 63, # 2, Feb. 1995, p. 148.
  • M. Freeman and P. Palffy-Muhoray, "On Mathematical and Physical Ladders", AJP, Vol. 53, #3, Mar. 1985, p. 276.
  • Mo- 8:  Freier and Anderson,  A Demonstration Handbook for Physics.
  • M- 30:  Richard Manliffe Sutton, Demonstration Experiments in Physics.
  • Robert Ehrlich, "Ladder Against the Wall", Why Toast Lands Jelly-Side Down, p. 60- 63.
  • James Ringlein, "Understanding and Illustrating the atomic origins of friction", APT 72 (7) July 2004, p. 884.
  • Mark Denny, "Meshchersky Ladders", TPT, Vol. 61, #4, Apr. 2023, p. 257.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.