A periodic wave (i. e., a wave pattern that repeats itself) is produced in a stretched string by a mechanical oscillator operating at a frequency of 465 Hz. This means that one point on the stretched string is pushed up and down at a regular frequency. The so-called "oscillator" is the source of the repeating waves. The linear density of the string is 0.00140 kg/m and the wavelength of the periodic wave is 0.0700 m.