Demonstrations

Beats - Oscilloscope

Code Number :	3B60.20
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 :	Constructive & Destructive, Interference of Sound Waves
Area of Study :	Acoustics
Equipment :	PA Amplifier, Frequency meters (2), Wave generators, Tektronix 2235 Oscilloscopes (2), Speakers (pair, large), Scaler-Timer (Nucleus).
Procedure :	The setup with the two generators and one or two oscilloscopes will show wave interference and addition but will not be audible. The setup with the speakers is an audible counterpart of the above demo. Input the generators into the amplifier and plug the amplifier into one speaker. As the two systems are operated together you will hear the interference pattern. The frequency counter is just so you are sure at what frequency you are operating, if needed with non-digital generators.

References

Ronald Newburgh, "An Alternative Approach to Explaining Beats", TPT, Vol. 44, # 2, Feb. 2006, p. 86.

Brian Andersson and Matthew Dykoski. "Demonstrating Beats with Springs and a Cart," TPT, Vol. 43, # 8, p. 490, (November 2005).

Derrick E. Boucher, "A Visual and Acoustic Demonstration of Beats and Interference," TPT, Vol. 37, # 3, p. 177, (March 1999).

Frazier Worth, "Beats: Video Monitors and Cameras," TPT, Vol. 34, # 6, p. 374, (Sept. 1996).

Robert W. Schramm, "Using a Stereo Tape Recorder as a Demonstration Device", TPT, Vol. 12, # 3, March 1974, p. 172.

Si- 4: Freier and Anderson, A Demonstration Handbook for Physics.

W-115: "Slinky Simulator - Coiled Spring," DICK and RAE Physics Demo Notebook.

W- 315: "Beats with a Drift," DICK and RAE Physics Demo Notebook.

Paul Gluck, "You Can Illustrate Beats Without the Usual Tuning Forks", Physics Education, Vol. 39, (3), May 2004, p. 241.

Ron Hipschman, "Walking Beats," Exploratorium Cookbook, p. 117.1 - 117.2.

Mail Questions and Comments to: Dale Stille