Answer:
[tex]T = 175.6 N[/tex]
Explanation:
As we know that string is vibrating in third harmonic
So we will have
[tex]L = 3\frac{\lambda}{2}[/tex]
so we have
[tex]0.79 = \frac{3}{2}\lambda[/tex]
so we have
[tex]\lambda = \frac{2}{3}(0.79)[/tex]
[tex]\lambda = 0.527[/tex]
we know that frequency of the wave is given as
f = 500 Hz
now we know that
speed of the wave is
[tex]v = frequency \times wavelength[/tex]
[tex]v = (500)(0.527)[/tex]
[tex]v = 263.3 m/s[/tex]
now we have
[tex]v = \sqrt{\frac{T}{m/L}}[/tex]
so we have
[tex]263.3 \sqrt{\frac{T}{(0.002/0.79)}}[/tex]
[tex]T = 175.6 N[/tex]