19724102

also called Doppler contunity equation??

In classical physics, where the speeds of source and the receiver relative to the medium are lower than the velocity of waves in the medium, the relationship between observed frequency f and emitted frequency f0 is given by: f = \left( \frac{v + v_r}{v + v_{s}} \right) f_0 \, where v \; is the velocity of waves in the medium v_{r} \, is the velocity of the receiver relative to the medium; positive if the receiver is moving towards the source. v_{s} \, is the velocity of the source relative to the medium; positive if the source is moving away from the receiver. The frequency is decreased if either is moving away from the other. The above formula works for sound wave if and only if the speeds of the source and receiver relative to the medium are slower than the speed of sound. See also Sonic boom. source: http://en.wikipedia.org/wiki/Doppler_equations

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <apply> <eq/> <ci type="function">f</ci> <apply> <times/> <apply> <divide/> <apply> <plus/> <ci>v</ci> <ci> <msub> <mi>v</mi> <mi>r</mi> </msub> </ci> </apply> <apply> <plus/> <ci>v</ci> <ci> <msub> <mi>v</mi> <mi>s</mi> </msub> </ci> </apply> </apply> <ci> <msub> <mi>f</mi> <mn>0</mn> </msub> </ci> </apply> </apply> </math>

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <mrow> <mi>f</mi> <mo>=</mo> <mrow> <mfenced close=")" open="("> <mfrac> <mrow> <mi>v</mi> <mo>+</mo> <msub> <mi>v</mi> <mi>r</mi> </msub> </mrow> <mrow> <mi>v</mi> <mo>+</mo> <msub> <mi>v</mi> <mi>s</mi> </msub> </mrow> </mfrac> </mfenced> <mo>&InvisibleTimes;</mo> <msub> <mi>f</mi> <mn>0</mn> </msub> </mrow> </mrow> </math>

f = \left( \frac{v + v_r}{v + v_{s}} \right) f_0

<math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <semantics> <mrow> <mi>f</mi> <mo>=</mo> <mfenced close=")" open="("> <mfrac> <mrow> <mi>v</mi> <mo>+</mo> <msub> <mi>v</mi> <mi>r</mi> </msub> </mrow> <mrow> <mi>v</mi> <mo>+</mo> <msub> <mi>v</mi> <mi>s</mi> </msub> </mrow> </mfrac> </mfenced> <msub> <mi>f</mi> <mn>0</mn> </msub> </mrow> <annotation encoding="SnuggleTeX">\[ f = \left( \frac{v + v_r}{v + v_{s}} \right) f_0 \]</annotation> </semantics> </math>