Bob is standing at a distance of 100 m from the center of circular train track with radius R= 50 m, observing a train moving with a constant speed of v = 20 m/s. If the motion ofthe train creates a sound with frequency f = 300 Hz (heard by the observer on the train),a) what are the highest and the lowest frequencies that Bob hears? (Take the speed ofsound in air to be 340 m/s)b)If he measures the sound level of 50 db when the train is at its farthest distance fromhim, what is the maximum sound level he measures?

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