standing wave的問題?

The wavelength 入 produced by a vibrating string is related to the length of the string L by the following equation:

L = (n/2)入
where n (a +ve integer) is the number of loops formed by the standing wave.
Hence, 入 = 2L/n

The smaller the value for n, the longer is the wavelength. Since the lowest integer value for n is "one", thus we have 入 = 2L = 2 x 80 cm = 160 cm

入 equals to infinity if and only if n = 0 (i.e. zero loop is formed) . But this means that the string is not vibrating, there is NO standing wave produced. Thus the question on "wavelength" is irrelevant.

You may refer to the web-page below for the above formula:

http://www.webassign.net/question_assets/tamucolphysmechl1/lab_7/manual.html