Physics (AS & A Level) · May / June 2022 · Paper 11 · Question 24

A car is travelling at a constant velocity directly towards a man standing in the middle of the road. The driver sounds the car's horn as a warning. The horn emits a sound wave of constant frequency. The frequency of the sound heard by the man is different from the frequency of the sound emitted by the horn. Which statement is correct?

1. AThe frequency of the sound emitted by the horn is greater than the frequency of the sound heard by the man.
2. BThe frequency of the sound heard by the man depends on the distance between the car and the man.
3. CThe sound waves continually accelerate as they move from the horn to the man.
4. DThe wavelength of the sound heard by the man is less than the wavelength of the sound emitted by the horn.

As printed in the paper