Doppler Effect (ν' = ν₀ × (v ± v_o)/(v ∓ v_s))
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ν' = ν₀ × (v ± v_o)/(v ∓ v_s)
What each symbol means
| Symbol | What it stands for |
|---|---|
| v | Speed of sound in medium (m/s) |
| v_o | Speed of observer (m/s) |
| v_s | Speed of source (m/s) |
| ν' | Apparent/observed frequency (Hz) |
| ν₀ | Actual source frequency (Hz) |
When to use this
Upper signs (+v_o, -v_s): observer moves TOWARDS source / source moves TOWARDS observer. Lower signs (-v_o, +v_s): observer moves AWAY / source moves AWAY. Convention: all velocities measured along the line joining source and observer. When source approaches: wavelength compressed, frequency increases. When source recedes: wavelength stretched, frequency decreases.