تماشای ویدئو Introduction to the doppler effect Mechanical waves and sound Physics Khan Academy از آی-ویدئو
Introduction to the Doppler Effect. Created by Sal Khan.
Watch the next lesson: https://www.khanacademy.org/science/physics/mechanical-waves-and-sound/doppler-effect/v/doppler-effect-formula-for-observed-frequency?utm_source=YT