Answer:
Explanation:
Given
Distance between loud speaker is [tex]d=4\ m[/tex]
For destructive interference phase difference is given by
[tex]\Delta \phi =\frac{\lambda }{2}[/tex]
Distance of observer from one speaker
[tex]x_1=0.5L+0.35[/tex]
Distance of observer from second speaker
[tex]x_2=0.5L-0.35[/tex]
Phase difference
[tex]\Delta \phi =x_1-x_2=(0.5L+0.35)-(0.5L-0.35)[/tex]
[tex]\Delta \phi =0.7\ m[/tex]
therefore the wavelength of wave is
[tex]\Delta \phi =\frac{\lambda }{2}[/tex]
[tex]\lambda =0.7\times 2=1.4\ m[/tex]
frequency corresponding to this wavelength
[tex]f=\frac{v}{\lambda }[/tex]
where v=velocity of sound
[tex]=\frac{340}{1.4}=242.84\ Hz[/tex]
For maximum intensity of sound
Phase difference [tex]\Delta \phi =\lambda[/tex]
[tex]\lambda =0.7\ m[/tex]
Frequency corresponding to this wavelength is [tex]f=\frac{340}{0.7}=485.71\ Hz[/tex]