As a car moving at constant velocity passes an observer at rest, the observer notices a change in the frequency of the sound produced by the car. Which statement is correct?
- AThe change in frequency is greater as the car moves away than as it approaches.
- BThe greater the speed of the car, the greater the change in observed frequency.
- CThe observed frequency is lower as the car moves towards the observer and higher as the car moves away from the observer.
- DThe volume of the sound heard by the observer does not change as the car approaches.