Concept Overview
Demonstration of Inertia
Lecturer Procedures
Steps to Follow
Pull sharply on the paper.
Expected Result
Rod will remain standing.
Historical References; Taken from original work of Percy H. Carr, 1970
“Do not, please, give the often given explanation that the paper is out from under the pencil before the pencil can move. The pencil does move, but the design of the experiment has reduced the motion to an acceptable level which does not move the pencil out of its narrow stable regime. I recommend an explanation along the lines given in M-D6.
“Usually in a case like this I take time after the experiment to comment that this is a nice parlor trick that some might like to try sometime. Then I review concisely the important points in the experiment design as I have done here at the beginning.”
Note:
This demonstration requires advanced practice to keep the rod standing vertically.