Boy Phat is sitting in a car, assuming it has a 120 hertz horn, while the car is moving at a speed of 20.0 m/s in still air. If the speed of sound in air is 343 m/s, what frequency will Boy Phat hear when the car approaches and after the car passes? a)What frequency will the person on the side of the road notice as the car approaches and after it passes? b)What frequency was observed by Boy Phat traveling in the car?