Answer:
f = 735 Hz
Explanation:
given,
Person distance from speakers
r₁ = 4.1 m r₂ = 4.8 m
Path difference
d = r₂ - r₁ = 4.8 - 4.1 = 0.7 m
For destructive interference
[tex]d = \dfrac{n\lambda}{2}[/tex]
where, n = 1, 3,5..
we know, λ = v/f
[tex]d = \dfrac{n v}{2f}[/tex]
v is the speed of the sound = 343 m/s
f is the frequency
[tex]f = \dfrac{n v}{2d}[/tex]
for n = 1
[tex]f = \dfrac{343}{2\times 0.7}[/tex]
f = 245 Hz
for n = 3
[tex]f = \dfrac{3\times 343}{2\times 0.7}[/tex]
f = 735 Hz
Hence,the second lowest frequency of the destructive interference is 735 Hz.