Physics HL

Chapter 16: The Doppler Effect

Build full Doppler-effect fluency from wavefront geometry and low-speed light shifts to sound formulas for moving sources, moving observers, and reflected-wave measurements.

1 simulation entries

Simulation: Wavefront Doppler Studio

Control source and observer velocities, inspect wavefront bunching/stretching, and compare geometry with computed observed frequency.

Appears in: 16.1 The Doppler Effect at Low Speeds, 16.2 The Doppler Effect for Light and Red-Shift, 16.3 The Doppler Effect for Sound: Moving Source, 16.4 Moving Observer, Combined Motion, and Reflections

Doppler Effect Lab

Observed frequency

736.31 Hz

Wavefront spacing near observer

0.462 m

Source-frame wavelength

0.500 m

Wave speed relative to observer

340.00 m/s

Wavefront geometry (positive velocity points to the right)

SourceObserverCloser circles in front of a moving source mean shorter wavelength and higher observed frequency.
Sign convention in this lab: source starts left of observer and positive velocity is to the right. The sound-frequency model isf' = f (v - v_o)/(v - v_s)where negative observer velocity means moving toward the source.