Calculadora de Frequência Doppler — Formula

Doppler Effect for Sound

The Doppler effect shifts the observed frequency when the source or observer is moving relative to the medium.

Formula

f_obs = f_s * (c + v_obs) / (c + v_src)

Sign convention: v_obs is positive when moving toward the source; v_src is positive when moving away from the observer.

  • Source approaching: lower denominator, higher f_obs
  • Source receding: higher denominator, lower f_obs

    • Exemplo Resolvido

    A 440 Hz siren moves away at 30 m/s, observer stationary.

    1. f_obs = 440 * (343 + 0) / (343 + 30)
    2. f_obs = 440 * 343 / 373
    3. f_obs = 440 * 0.9196
    4. f_obs = 404.6 Hz (lower pitch)