Google’s top ten videos

Here is a list of the ten google videos of 2006 chosen by Google’s Research blog.

Excellent physics demonstrations

While I was reading the latest edition of Make magazine in a Chapters bookstore, I came across this really interesting physics demonstration: a bar that is on top of two wheels rotating in opposite directions. At first you’ll think the bar will just slide of but it actually moves back and forth on top of the wheels if they spin the right way. If not the bar falls off. If you do the math, if the wheels spin in one direction the force on the bar is opposite to the acceleration (causing ocillatory motion like in a mass-spring system), but if you spin them the other way the force on the bar is in the direction of the acceleration, causing positive feedback. The magaine has a link in it that redirects you to the link below. The link is part of a website showing other good physics demonstrations.

Here’s the link:

http://www.lhup.edu/~dsimanek/scenario/demos.htm#plank