In: Physics
3. You are listening to two fire trucks with sirens blaring headed to a fire down the street. One has passed you and is headed away from you already. The other is headed down the street toward you. You know that these fire engine sirens play a note at a frequency of 700 Hz (20 points).
(a) You listen to the sounds of the two sirens and you notice a fast “wobbling” of the sounds from the two sirens at a rate of 20 beats per second. If both fire engines are traveling at the same speed, at what speed do the trucks travel?
(b) If you hear one of the sirens at a sound level of 80 dB at a distance of 30 meters, what is the sound level for a fireman sitting on the truck at a distance of only 1.5 meters away from the siren? Consider the case when the fire engine is stationary.
(c) What is the pressure amplitude of this sound wave heard at a distance of 30 meters? Consider the case when the fire engine is stationary.