This paper serves to update an elegant experiment published in The Physics Teacher to measure the speed of a pulse on a taut metal wire.1 Unfortunately, commercially available units2 that serve the same purpose are priced outside the range of most high school or college physics teaching laboratories. Wakeland et al. show how an affordable adaptation of the traditional standing wave apparatus using taut metal wire and horseshoe magnets can be used to measure the speed of a pulse by using an oscilloscope to measure an induced voltage in the wire as the pulse transverses the middle of the magnets, which are a known distance apart.

I am indebted to Frank Noschese for this month's column. Frank has a fantastic blog and video list. He uses these videos in his class and asks the students to determine if they show a Physics Win or a Physics Fail. He will hook his students at the beginning of a new unit with a video and then refer back to that video at the end of the unit. Check out Frank's blog at: fnoschese. wordpress.com/2010/07/21/win-fail-physics-an-introduction/.