A physics professor demonstrates the Doppler effect by tying a 900 Hz sound generator to a 1.0- m -long rope and whirling it around her head in a horizontal circle at 100 rpm .
1. What is the difference between the highest frequency heard by a student in the classroom and the initial frequency of the sound generator?
2. What is the difference between the lowest frequency heard by a student in the classroom and the initial frequency of the sound generator?