Animation of the Doppler Effect

This Doppler Effect simulation allows the student to control the speed of a sound source while circular wave fronts are periodically produced to illustrate the crests of the sound waves emitted by the source. The student can observe the effect of source speed on the wave front pattern. Source speeds above and below the speed of sound are permitted so that a sonic boom can be illustrated. Lecture notes for the teacher on the Doppler Effect are also provided. Most students have heard the Doppler Effect and can describe or imitate the resulting effect on perceived sound pitch, but describing why the changes in pitch occur can be difficult for many. This simulation allows the student to explore the relationship between the speed of the source of the sound and the compression or extension of the apparent wavelength, and hence frequency, that results. The relationship of the wavelengths and frequency or pitch can be investigated through exploration. The lecture notes provided for the teacher provide conceptual illustration of the Doppler Effect as well as a mathematical extension suitable for AP Physics or other mathematically advanced students.