The example in the river was to show how sound and light waves might
travel indicating how the doppler effect works. In real life, how does
doppler effect work? Check all boxes that show a situation which would
produce the doppler effect."
-the sound producer is stationary and the observer moves.
-the observer is stationary and the sound producer moves.
-both the observer and the sound producer can move towards or away from each
other
-the observer and the producer move in the same direction at the same speed
-neither observer or producer move, but the producer changes the frequency emitted.
-Other