Double Cone and Diverging Ways

Concept Overview

A system seeks minimum potential energy.

Lecturer Procedure

Steps to Follow

1. Set the cone in the middle of the diverging ways.
2. Ask for predictions as to which direction it will roll.
3. Release cone.

Expected Result

Most students will expect it to roll toward the converged end, as the diverged end is elevated.  However, it will roll toward the diverged end.  The angle of the cone makes it so that the center of mass of the cone is actually lowered when traveling toward the diverging end.

Historical References; Taken from original work of Percy H. Carr, 1970 

 “The experiment is more of an illusion than anything else and is built on such as small scale that it is effective only for a small group which can cluster around and see the details of construction and behavior.”

Video Demonstration

There is no audio for this recording.