A small source of sound vibrating at frequency `500 Hz` is rotated in a circle of radius `100//pi cm` at a constant angular speed of `5.0` revolutions per second. A listener situates himself in the plane of the circle. Find the minimum and the maximum frequency of the sound observed. Speed of sound in air `= 332 m//s`.

Explanation

Speed of source `v_(s) = r omega = (1)/(pi) xx 2 pi xx 5 = 10 m//s`,
Speed of sound `v = 332 m//s`
The listener will hear maximum frequency when source is in position `①`
`f_(max) = f((v)/(v - v_(s))) = 500((322)/(332 - 10)) = 516 Hz`
The listener will hear minimum frequency when source is in position `②`
`f_(min) = f((v)/(v + v_(s))) = 500((322)/(332 - 10)) = 485 Hz`