The Doppler effect is the change in frequency (pitch) of a wave when the source or observer is moving relative to the medium. A sound source moving toward you has a higher apparent frequency; moving away has lower frequency. Used in radar, medical ultrasound, and astronomy.
⭐
Did You Know?
Christian Doppler first described this effect in 1842 for light waves in binary stars. A Viennese railway company tested it two years later by having musicians play on a moving train.
References
🔒
100% Miễn phí
Không cần đăng ký
✓
Chính xác
Công thức đã xác minh
⚡
Tức thì
Kết quả khi nhập
📱
Sẵn sàng di động
Mọi thiết bị