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ERIC Number: EJ977823
Record Type: Journal
Publication Date: 2012-Jan
Pages: 5
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0031-9120
EISSN: N/A
Teaching Wave Propagation and the Emergence of Viete's Formula
Cullerne, J. P.; Goekjian, M. C. Dunn
Physics Education, v47 n1 p87-91 Jan 2012
The well-known result for the frequency of a simple spring-mass system may be combined with elementary concepts like speed = wavelength x frequency to obtain wave propagation speeds for an infinite chain of springs and masses (masses "m" held apart at equilibrium distance "a" by springs of stiffness "gamma"). These propagation speeds are dependent on the wavelength of the wave. The dispersion is easily investigated by considering normal modes of increasing wavelength. This investigation also elegantly highlights how the dispersion physically arises in the form of "effective spring constants" due to the way in which neighbouring springs contribute to the propagation of each of the normal modes. The resulting propagation speeds v(lambda) are given by an expression [image omitted], which in the limit of large lambda becomes [image omitted]. This of course means that [image omitted]--the serendipitous emergence of what turns out to be Viete's formula for pi in terms of nested roots of 2. (Contains 3 figures.)
Institute of Physics Publishing. The Public Ledger Building Suite 929, 150 South Independence Mall West, Philadelphia, PA 19106. Tel: 215-627-0880; Fax: 215-627-0879; e-mail: info@ioppubusa.com; Web site: http://journals.iop.org
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A