Demonstrations

Driven Resonance - Pasco Oscillator and Rotating Mass on a Spring

Code Number :	3A60.40
Disclaimer:	Reprinted by permission of Dick Berg, University of Maryland, for use on this website. The demonstrations contained and referenced herein are listed for the purposes of cataloging and describing physics demonstrations which should be conducted only under the direction of a trained instructional support professional or physicist. These demonstrations are not presented for the purpose of being conducted by persons unconnected to this Facility and/or persons not consulting with or being supervised by the recognized instructional support professional or physicist and his/her staff. The University is responsible only for those demonstrations carried out using its own equipment using established safety and scheduling policies, and bears no responsibility for those choosing to use this source material for their own purposes. All demonstrations described and contained herein are public domain, and can also be found in reference materials in libraries, bookstores, and electronic sources. Further information regarding legal liability in use of demonstrations and labs will be found on the web site Injuries in School/College Laboratories in USA. The University of Iowa Disclaimers: University of Iowa Disclaimer All Rights Reserved..
Condition :	Good
Principle :	Simple Harmonic Motion
Area of Study :	Acoustics
Equipment :	Pasco harmonic motion machine, Masses for machine (2) (50 g ea.), Rotating mass on a spring app.
Procedure :	Practice will be needed for the Pasco machine. Resonance for the Pasco machine should be around 179 to 181. The rotating mass has masses that can be added which will allow it to rotate out of balance. Hang the rotating mass by its spring on a very sturdy rod and crossrbar. Spin the mass and as it slows down in will eventually send the system into resonance as evidenced by a very large oscillation.

References

Michael C. Lopresto and Paul R. Holody, "Measuring the Damping Constant for Underdamped Harmonic Motion," TPT, Vol. 40, # 1, p. 22 (Jan. 2003).

A John Mallinckrodt, "Drag Forces", TPT, Vol. 41, # 5, May. 2003, p. 261.

Michael C. LoPresto, Paul R. Holody, "Drag Forces, Authors' Response", TPT, Vol. 41, # 5, May 2003, p. 262.

Chris A. Gaffney and David Kagan, "Beats in an Oscillator Near Resonance," TPT, Vol. 40, # 7, p. 405, (Oct. 2002).

Walter Roy Mellen, "Spring String Swing Thing", TPT, Vol. 32, # 2, Feb. 1994, p. 122.

Fabrizio Pinto, "Parametric Resonance: An Introductory Experiment", TPT, Vol. 31, # 6, Sept. 1993, p. 336.

W. Herreman, "The Transient Phenomena of Forced Vibrations", TPT, Vol. 29, # 3, Mar. 1991, p. 187.

P. Coullet, J. M. Gilli, M. Monticelli, and N. Vandenberghe, "A Damped Pendulum Forced With a Constant Torque", AJP, Vol. 73, # 12, Dec. 2005, p. 1122.

Lee E. Larson, "Interfacing the PASCO Simple Harmonic Motion Apparatus to a Microcomputer", AJP, Vol. 55, # 7, July 1987, p. 667.

P. J. Ouseph and John P. Ouseph, "Electromagnetically Driven Resonance Apparatus", AJP, Vol. 55, # 12, Dec. 1987, p. 1126.

Mark A. Heald, "How Do You Know When You've Got Critical Damping?", AJP, Vol. 46, # 10, Oct. 1978, p. 989.

Mail Questions and Comments to: Dale Stille