Hi guys, Welcome to the Advanced Video Search Engine, and you are watching Doppler effect for a moving observer | Mechanical waves and sound | Physics | Khan Academy. That video is uploaded by khanacademymedicine at 2014-07-01T13:42:55-07:00. We are promoting this video only for entertainment and educational purpose only. So, I hope you like & enjoy it. [2TTu0TvB6N0]