Answer:
The part of the wave is the Amplitude.
Reason: The amplitude of light waves is responsible for our perception of brightness, with larger amplitudes appearing brighter than lower amplitudes.
Step-by-step explanation:
The amplitude of light waves is responsible for our perception of brightness, with larger amplitudes appearing brighter than lower amplitudes.
Thus, when you turn up the brightness of the light so that you can better see, you are increasing the amplitude of the light wave, which in turn increases the intensity of the light, seen from the increased brightness of the flash light.