Physics (AS & A Level) · Oct / Nov 2021 · Paper 12 · Question 25

A train travels in a straight line at a constant speed of 30 m s–1. The train’s horn continuously emits sound of frequency 2400 Hz. A stationary observer stands next to the train track. The train approaches the stationary observer, passes him and then moves away. The speed of sound is 340 m s–1. What is the maximum difference in the frequencies of the sound heard by the stationary observer?

1. A190 Hz
2. B230 Hz
3. C430 Hz
4. D460 Hz

As printed in the paper