A car with the windows rolled down is traveling north on road u( speed of 21.0 m/s. A fire truck, traveling south at speed of 50.0 m/s, approaches with its siren producing sound at a frequency of 2450 Hz: (speed of sound in air 343 m/s) ( [0 points) (a) What frequency does the driver of the car observe aS the fire truck approaches? (b) What frequency does the driver of the car detect alter the fire truck passes her?