Doppler Frequency Calculator — सूत्र

## 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