Physics

Problem

Two whistles emit steady notes of frequencies

380\,\text{Hz}

and

385\,\text{Hz}

. The displacement of air at the listener’s position is a maximum at

t=0\,\text{s}

. At what earliest later time will the displacement again be a maximum? a)

2.6\times10^{-3}\,\text{s}

0.20\,\text{s}

0.10\,\text{s}

0.40\,\text{s}