The apparent change in frequency of sound wave due to the relative motion of source of sound of sound and observer is called Doppler’s effect. For example: You hear the high pitch of the siren of approaching ambulance and you notice dropping of pitch sudenly as ambulance passes you whic is dpppler effect. This phenomenon was first derived by Australian Scientist Doppler. So, it is Doppler’s effect.
Let ‘v’ be the velocity of sound ‘λ’ be the wavelength of sound wave and ‘f’ be the frequency.
$$\text {Then,} \: f = \frac {v}{\lambda } $$
Manu Kumar Khatry, Manoj Kumar Thapa, Bhesha Raj Adhikari, Arjun Kumar Gautam, Parashu Ram Poudel. Principle of Physics. Kathmandu: Ayam publication PVT LTD, 2010.
S.K. Gautam, J.M. Pradhan. A text Book of Physics. Kathmandu: Surya Publication, 2003.
The apparent change in frequency of sound wave due to the relative motion of source of sound of sound and observer is called Doppler’s effect.
When source of sound moves towards observer in rest, then wavelength of sound decreases. The apparent change in frequency is given by \(f’ = \frac {v}{v – u_s} \times f\).
When source of sound moves away from the observer in rest, the wavelength of sound wave. Therefore, apparent change in frequency is given by \(f’ = \frac {v}{v +u_S} \times f\).
When observer moves towards the source in rest, then apparent change in frequency is given by \( f’ = \left ( \frac {v + u_0}{v} \right ) f\).
When observer moves away from the source in rest then apparent change in frequency is given by \(f’ = \left ( \frac {v- u_0}{v} \right ) f\).
When source and observer moves towards each other then apparent change in frequency is given by \(f’ = \frac {v + u_0}{v –v_s}f\).
When source and observer moves away from each other then apparent change in frequency is given by \(f’ = \frac {v - u_0}{v + v_s}f\).
When source leads the observer then apparent change in frequency is given by \(f’ = \frac {v + u_0}{v + v_s}f\).
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Dipesh
If figure was also provided then it would a alot better but notes are awesome
Jan 10, 2017
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