Students will learn what the Doppler effect is and how to determine frequencies and speeds using the Doppler shift equations.
Question: How fast would a student playing an A note () have to move towards you in order for you to hear a G note ()?
Answer: We will use the Doppler shift equation for when the objects are getting closer together and solve for the speed of the student (the source).
Now we plug in the known values to solve for the velocity of the student.
Watch this Explanation
Time for Practice
- What changes about a wave in the Doppler effect: Frequency? Wavelength? Speed? Is it correct to say that if an ambulance is moving towards you the speed of the sound from its siren is faster than normal? Discuss.
- A friend plays an A note on her flute while hurtling toward you in her imaginary space craft at a speed of . What frequency do you hear just before she rams into you? Assume the speed of sound to be 343 m/s.
- How fast would a student playing an A note have to move towards you in order for you to hear a note ? Assume the speed of sound to be 343 m/s