The distance between a compression and the next rarefaction of a sound wave is 12.5cm.If the sound waves travel 750 m in 3 s,then find the number of waves produced in one second.
Answers
Compression and rarefaction in air – Compression and rarefaction are produced because of the disturbance in medium caused by sound wave. Sound wave propagates because of compression and rarefaction of the particles of the medium.
When an object starts vibrating, it creates disturbance in medium. Because of the disturbance particles of medium come closer to each other compare to their normal position on the other hand adjacent particles go farther to each other. Both happen simultaneously.
The region where particles are come closer to each other is called compression and region where particles go farther to each other is called rarefaction.
In the given figure straight lines are showing the normal position of air particles. Dense lines are showing the region of compression and less dense lines are showing region of rarefaction of air particles.
Speed of sound=750/3=250m/s
Wave length =2*distance between compression and rarefaction=2*12.5=25cm=0.25m
No. Of waves=speed/wavelength=frequency=1000