Question #2148b

1 Answer
Feb 24, 2017

google image

Given that the velocity of stationary wave produced in a stretched string depending on its tension (T)and its mass per unit length (m) is (V=270.9m/s)

As shown in above figure the wave lengths λi of first three harmonics are related with the length L of the stretched string as follows.

For first i th harmonic λi=2Lpi,

where pi is the number of loops produced in the given length L of the stretched string

For 1st harmonic wave length λ1=2L

For 2nd harmonic wave length λ2=2L2

For 3rdharmonic wave length λ2=2L3

So

For 1st harmonic, frequency

n1=Vλ1=V2L=270.9×102cms132.4cm=836.1Hz

For 2nd harmonic, frequency

n2=Vλ2=2V2L=2n1=1672.2Hz

For 3rd harmonic, frequency

n3=Vλ2=3V2L=3n1=2508.3Hz