Answer:
43.2 N
Explanation:
[tex]\lambda[/tex] = Wavelength = 0.75 m
f = Frequency = 40 Hz
m = Mass of string = 0.12 kg
L = Length of string = 2.5 m
[tex]\mu[/tex] = Linear density = [tex]\dfrac{m}{L}[/tex]
Velocity of wave is given by
[tex]v=\lambda f\\\Rightarrow v=0.75\times 40\\\Rightarrow v=30\ m/s[/tex]
The tension in string is given by
[tex]T=v^2\mu\\\Rightarrow T=30^2\times \dfrac{0.12}{2.5}\\\Rightarrow T=43.2\ N[/tex]
The tension in the string is 43.2 N
