Literaturnachweis - Detailanzeige
Autor/inn/en | Cros, Ana; Ferrer-Roca, Chantal |
---|---|
Titel | Excitation of Standing Waves by an Electric Toothbrush |
Quelle | In: Physics Teacher, 44 (2006) 9, S.578-579 (2 Seiten)Infoseite zur Zeitschrift
PDF als Volltext |
Sprache | englisch |
Dokumenttyp | gedruckt; online; Zeitschriftenaufsatz |
ISSN | 0031-921X |
DOI | 10.1119/1.2396773 |
Schlagwörter | Leitfaden; Unterricht; Lehrer; Scientific Concepts; Physics; Motion; Science Experiments; Scientific Methodology; Scientific Principles |
Abstract | There are a number of ways of exciting standing waves in ropes and springs using non-commercial vibrators such as loudspeakers, jigsaws, motors, or a simple tuning fork, including the rhythmical shaking of a handheld Slinky. We have come up with a very simple and cheap way of exciting stationary waves in a string, which anyone, particularly children, can try at home. It consists of using an electric toothbrush to produce a regular sideways motion that can be easily transmitted to an elastic cord. Most suitable for this experiment is the kind of unit that has a metal rod protruding from the front (see Fig. 1, which shows our Braun Oral-B®) to which a brush is normally affixed. The ends of the cord are attached to stands. Elastic cords that come with some school notebooks work well for this experiment, but a longer cord allows the observation of a larger number of modes. The toothbrush unit is placed near one end of the cord, which is wrapped once around the rod. As the toothbrush vibrates at a fixed frequency, standing waves (see Fig. 2) may be tuned by changing the tension of the cord while keeping its length constant. We have found up to five harmonics with a 150-cm cord. The toothbrush can be connected to a small potentiometer to reduce the dc voltage and hence the frequency of the motor, allowing the tuning of the standing waves with a fixed tension. (As Provided). |
Anmerkungen | American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail: pubs@aapt.org; Web site: http://scitation.aip.org/tpt |
Erfasst von | ERIC (Education Resources Information Center), Washington, DC |
Update | 2020/1/01 |