Question

A string vibrates in its first normal mode with a frequency of `220` vibrations `//s`. The vibrating segment is 70.0 cm long and has a mass of 1.20g.
(a) Find the tension in the string.
(b) Determine the frequency of vibration when the string vibrates in three segments.

Answer 1

Correct Answer - A::B::C
`(a) f = v/(2l) = sqrt((T//mu))/(2l)`
`:. T = 4l^(2)f^(2)mu `
`= (4)(0.7)^2(220)^2((1.2 xx (10^-3))/(0.7))`
= 163 n
(b) ` f_3 = 3f_1 = 3 xx 220 = 660 Hz.`