Answer:
1 m
Explanation:
given,
frequency emitted by the speaker,
f = 172 Hz
speed of sound,v = 344 m/s
distance of Point A = 8 m
[tex]wavelength = \dfrac{speed\ of\ sound}{frequency}[/tex]
[tex]\lambda= \dfrac{344}{172}[/tex]
λ = 2 m
For destructive interference
[tex]r_a - r_b = \dfrac{\lambda}{2}[/tex]
[tex] r_b =r_a - \dfrac{\lambda}{2}[/tex]
[tex] r_b = 8 - \dfrac{2}{2}[/tex]
[tex] r_b =7 m [/tex]
the closest you can be to B and be at a point of destructive interference
= r_a - r_b
= 8 - 7
= 1 m
