Research Papers in Physics and Astronomy


Date of this Version

January 1999


The Physics Teacher, Vol. 37, 24-27, Jan. 1999. Permission to use.


Billiard-ball collisions are frequently cited in introductory physics textbooks, usually as examples of elastic collisions. Many articles describing such collisions have appeared in this journal and elsewhere, but comparisons between theoretical results and actual collisions are rare, and most of the theoretical analyses have simply assumed friction to be negligible during the collision time. Students trying to simulate billiard-ball collisions on a popular simulation program such as Interactive Physics® may encounter interesting collisions, such as ones in which the cue ball is thrown up into the air when the frictional coefficients are set at even modest levels. We decided to use a video-analysis tool designed for the physics classroom (VideoPoint®) to examine a slow-motion film of a head-on collision made some years ago and currently available on Physics: Cinema Classics. In this paper, we compare some of the experimental data we obtained with theoretical results and the simulation results.

Included in

Physics Commons