Instructional Resources and Lecture Demonstrations

Code Number: 1K20.03

Demo Title: Friction Model

Condition: Good

Principle: Static friction surface models

Area of Study: Mechanics

Equipment:

Egg Crate foam surfaces, smooth and rough surfaces.

Procedure:

Use the egg crate foam surfaces and other rough and smooth surfaces, blocks, or flat surfaces to demonstrate what microscopic or surface features of two objects sliding over each other will contribute to their friction.

References:

Ching-Chi Chu, "Visualizing Amontons's Second Law: A Macroscopic Analogy for Microscopic Contact", TPT, Vol. 64, #2, Feb. 2026, p. 158.
Patton H. McGinley, "Cookie Sheet Friction", TPT, Vol. 11, #6, Sept. 1973, p. 362, also A Potpourri of Physics Teaching Ideas - Mechanics, p. 8.
James Ringlein and Mark O. Robbins, "Understanding and Illustrating the Atomic Origins of Friction", AJP, Vol. 72, #7, July 2004, p. 884.

Friction Models at 15.44

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.

1K20.03 - Friction Model