The diagram illustrates a car moving from point X to point Y in a straight path at a steady speed between person P and person Q. As it moves, the car keeps its horn sounding all the time. The horn produces sound with a fixed frequency. Which of the following statements about the sounds heard by person P and person Q during the car’s movement are correct? 1. Person P hears a sound whose frequency increases. 2. Person Q hears a sound whose frequency decreases. 3. Person Q always hears a sound with a higher frequency than person P.
- A1, 2 and 3
- B1 and 2 only
- C3 only
- Dnone of them