What properties of sound determine the pitch of sound? How is this affected by motion of the sound source?

What properties of sound determine the pitch of sound? How is this affected by motion of the sound source?



can some one plz help me asap!What properties of sound determine the pitch of sound? How is this affected by motion of the sound source?Pitch is a common term we give for frequency. So changing the pitch means changing the frequency of sound. Sound, like all things, travels a distance L = velocity X time = vt.



If we set L = wavelength, then the time to travel one wavelength is called the periiod T. And frequency f = 1/T, the reciprocal of the period. So when L is wavelength, we have L = vT = v/f. This means, for a fixed speed of sound v, the wave length of that sound decreases as its frequency, its pitch goes higher.



Or stated in reverse, f = v/L, the frequency increases as the wave length decreases. Now what happens when the source of that sound is moving? If its moving toward us, then V %26gt; v is the apparent velocity of sound. That is, the apparent velocity is just v + U = V where U is the velocity of the source. And, from F = V/L %26gt; v/L = f, we see that F %26gt; f. In other words, when the source is coming at us, we hear a higher pitch F %26gt; f than when the source is standing still.



And the reverse, with the source moving away from us, gives us a lower pitch because the relative velocity of sound is now less than the standing still velocity. That is v - U is the apparent velocity so the frequency f decreases.What properties of sound determine the pitch of sound? How is this affected by motion of the sound source?frequency

the more the frequency the higher the pitch