I have done demonstrations of audible beats with tone bars, with function generators and speakers, and with resonating columns, and also visible beats with combs.1 In looking for a new beats demonstration, I regretted never having taken a picture of an overpass with wire fencing on both sides: the otherwise identical fencing shows visual beats because the two repeating patterns are at different distances from the observer.
REFERENCES
1.
Peter
Melzer
, “Beat production analogy using pocket combs
,” Phys. Teach.
14
, 120
(1976
).2.
For higher-quality templates, see EPAPS Document E-PHTEAH-43-012508.
This document may be retrieved via the EPAPS homepage (http://www.aip.org/pubservs/epaps.html) or from ftp.aip.org in the directory epaps in the phys_teach folder. See the EPAPS homepage for more information.
3.
A similar pattern may be found in Paul Tipler, Physics for Scientists and Engineers, 3rd ed. (Worth, New York, 1990), p. 453.
This content is only available via PDF.
© 2005 American Association of Physics Teachers.
2005
American Association of Physics Teachers
AAPT members receive access to The Physics Teacher and the American Journal of Physics as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.