When a wave source moves relative to an observer, wavefront spacing changes. Wave speed in the medium stays constant, so wavelength and observed frequency change together.
This question is about sound waves.
A buzzer is an electrical device that produces sound.
The frequency of sound produced by the buzzer is 1400 Hz .
Two students use this method to investigate sound from a moving source.
Student A connects a piece of string to the buzzer.
She spins round so that the buzzer moves in a horizontal circular path.
- she spins round at a slow speed
- she then spins round at a high speed
Student B stands several metres away from student A.
The sound heard by student A is different to the sound heard by student B.
Discuss the differences in the sounds heard by student A and student B.