A 400 Photogate for 50 or Less

摘要

I able in introductory physics,butthe price can be prohibitive for theaverage high school teacher.I havedesigned several photogates that onecan construct for less than 50 withjust a little soldering skill. The pho-togate featured here sells for nearly400 in science catalogs and youcan build it for around 50 depend-ing on the case that you use.