This web page contains problems that supplement Chapter 4 on contact forces and the momentum principle, in the introductory textbook Matter and Interactions by Ruth Chabay and Bruce Sherwood. Topics include tension, normal forces, uniform circular motion, tangential forces, and 2-D and 3-D ball-and-spring models.  Modern physics is introduced as students calculate approximate length and stiffness of an interatomic bond in a simple cubic lattice. Each problem can be viewed separately, with solutions, or downloaded as a pdf file.

The site includes videos showing solutions to many of the problems. These can be followed with RSS or as podcasts from iTunes. Instructors are encouraged to submit their own problems and solutions to the web site. Problems should be submitted in LaTex.

EDITOR'S NOTE: Although this material is organized to support Matter and Interactions by Chabay and Sherwood, most of the problems can be used with other introductory physics texts. Additional information about the pedagogy behind Matter and Interactions, which emphasizes student modeling and a modern perspective, can be found at
Matter and Interactions Home Page

For a cost-free article by the authors on implementation of Matter and Interactions in the introductory physics classroom, SEE RELATED ITEMS on this page.