The mouth of the river is where light penetration is most likely the lowest
20000000 kilometers
20000000 killometers
diffraction
65-35% light penetration.
photic zone and aphotic zone
Red light.
The lowest point on a Sound or light wave is called a trough.
Zone away from shore upto effective light penetration .
Please be careful when crossing the stream. A stream of light suddenly lit up the whole room.
The light will stream through the window in the morning. The water will stream through the hose.
In the "visible" light it is violet.
Red, because it has the lowest frequency in visible light