A 1.30-m string is held fixed at both ends.When driven by a 140-Hz source,the string vibrates in 4 distinct segments.What is the natural fundamental frequency of the string?
A)35.0 Hz
B)70.0 Hz
C)215 Hz
D)431 Hz
E)45.5 Hz

Question

Quizplus · Accepted Answer

When the string vibrates in 4 distinct segments, it is in its 4th harmonic. The fundamental frequency (1st harmonic) is a quarter of the 4th harmonic's frequency. Given the 4th harmonic is 140 Hz, the fundamental frequency is 140 Hz / 4 = 35.0 Hz.

A 130-M String Is Held Fixed at Both Ends