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1. A car drives by at 20mph, with a violinist in it playing a song. The speed of sound is 343 m/s. The violin is actually playing at 800Hz, what frequency do you hear before and after the car passes you?

User Tyler Eich
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1 Answer

6 votes

Answer:

frequency when car is approaching comes out to be 821 Hz

car is moving away from the object comes out to be 780 Hz

Step-by-step explanation:

car speed = 20 mph = 8.94 m/s

speed of sound = 343 m/s

violin frequency = 800 Hz

when car is approaching:


f^(')= f((c+v_0)/(c-v_s)) =800((343+0)/(343-8.94)) =821 Hz

when car is moving away


f^(')= f((c+v_0)/(c+v_s)) =800((343+0)/(343+8.94)) =780Hz

hence the frequency when car is approaching comes out to be 821 Hz

and when the car is moving away from the object comes out to be 780 Hz

User Mbrochh
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