In each case the equation is given in the graphic above:


Q1. As in the example given in the text and the diagram above, an emergency vehicle sounds a siren with a frequency of 800Hz, the speed of sound in air is given as 343 m/s. From this information calculate the perceived frequency of the siren from the perspective of the observer if the vehicle is approaching at 30 m/s.


Q2a. What is the frequency heard by a person driving at 15 m/s toward a blowing factory whistle (800.Hz) if the speed of sound is 340.6 m/s?


Q2b. From the previous problem, what frequency would he hear after passing the factory if he continues at the same speed?


Q3. You are riding a bicycle along the road at 15 km/h, going in the same direction as an ambulance which is approaching you from behind at 60 km/h. You can hear the 700Hz siren of the ambulance behind you as the ambulance approaches you. What is the change in sound frequency after it passes you, if the speed of sound in air is 343 m/s?


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