Re: moving wall laser demo

["Daniel L. MacIsaac" <Dan.MacIsaac@NAU.EDU>]

Gene:

Do you have a sketch or picture of this setup?  I'd like to recreate it
in my own class.  How long a rod, and what metal?  A sewing pin, a nail
or what for the rotating pin?

Dan M

Dan MacIsaac, Assistant Professor of Physics and Astronomy, Northern AZ Univ
danmac@nau.edu          http://purcell.phy.nau.edu         PHYS-L list owner

> We do a "bend the wall" demo on our stone walls.  We attached the end of a
> long metal rod to the wall with some clay.  at the other end we have a small
> mirror attached to a pin and set the pin under the rod as if you were doing
> an expansion of metal experiment.  When a laser is shining on the mirror and
> the wall is even slightly pressed within a couple of meters of the rod, you
> can get a major deflection.  The setup amplifies the movement very well and
> can get the laser dot to travel across a few meters.