Lesson 5: The Doppler Effect As a train approaches you, the bell's pitch appears to seems to called the Doppler Effect. Why does the Doppler Effect Happen? C and then as the train moves away from you. This change in pitch is . . ● ● ● When an airplane is stationary, the When the plane moves forward, the in pitch. and any all hear the won't notice any change of the plane. This is because the pilot hears the The sound waves in front of the plane get squished together, and therefore the wavelength Meanwhile, the wavelengths behind the plane are When wavelength decreases, Therefore, an observer standing in front of an airplane hears an apparent pitch that is than the true pitch. Therefore, an observer behind the airplane hears an apparent pitch which is than the true pitch.

Lesson 5: The Doppler Effect As a train approaches you, the bell's pitch appears to seems to called the Doppler Effect. Why does the Doppler Effect Happen? C and then as the train moves away from you. This change in pitch is . . ● ● ● When an airplane is stationary, the When the plane moves forward, the in pitch. and any all hear the won't notice any change of the plane. This is because the pilot hears the The sound waves in front of the plane get squished together, and therefore the wavelength Meanwhile, the wavelengths behind the plane are When wavelength decreases, Therefore, an observer standing in front of an airplane hears an apparent pitch that is than the true pitch. Therefore, an observer behind the airplane hears an apparent pitch which is than the true pitch.