Physics (AS & A Level) · Oct / Nov 2016 · Paper 12 · Question 25

A man standing next to a stationary train hears sound of frequency 400 Hz emitted from the train's horn. The train then moves directly away from the man and sounds its horn when it has a speed of 50 m s–1. The speed of sound is 340 m s–1. What is the difference in frequency of the sound heard by the man on the two occasions?

1. A51 Hz
2. B69 Hz
3. C349 Hz
4. D469 Hz

As printed in the paper