(હવામાં ધ્વનિની ઝડપ $=330\, ms^{-1}$)
(According to Doppler effect in sound)
\(f^{\prime}=\left(\frac{v+u}{v-u}\right) f\)
where \(f=\) original frequency of source of sound
\(f^{\prime}=\) Apparent frequency of source because of the relative motion between source and observer.
\(f^{\prime}=\left(\frac{330+220}{330-220}\right) 1000=5000 \mathrm{Hz}\)
(જયાં $ {I_0} $ થ્રેશોલ્ડ તીવ્રતા)