Question

Two speakers produce identical harmonic waves as in the figure below. If the two waves are 90 degree out of phase when they arrive at your ear, what is the minimum distance between the speakers in terms of the wavelength? (Use the following as necessary: lambda.) Delta d =

Answer 1

phase difference $\triangle \phi$ =90

basing on the concept of waves and oscillations

$\triangle \phi =2\pi /\lambda (\triangle d)$

$90 =2\pi /\lambda (\triangle d)$

$90\lambda/2\pi = (\triangle d)$

therefore the mionimum distances $(\triangle d)=\lambda /4$