1. 650 nm = red, 580 nm = yellow, 450 nm = blue
QUESTION:
Which of the following characteristics of electromagnetic radiation is not associated with what we perceive as color? A. wavelength, B. frequency C. wave speed, D. photon energy
Wavelength is associated with color. Visible spectrum ranges from 400 to 800 nm. Examples:
650 nm = red, 580 nm = yellow, 450 nm = blue
SCRIPT:
Which of the following characteristics of electromagnetic radiation is associated with what we perceive as color? A. wavelength, B. frequency C. wave speed, D. photon energy
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Wavelength is associated with color. For us to be able to see electromagnetic radiation, its wavelength must be between 400 and 800 nanometers.
This is known as the visible spectrum.
For example, we perceive electromagnetic radiation with a wavelength of 650 nm
HIGHLIGHT 650 nm=red
As red.
We perceive electromagnetic radiation with a wavelength of 580 nm as yellow.
HIGHLIGHT 580 nm=yellow
And we perceive electromagnetic radiation with a wavelength of 450 nm as blue.
HIGHLIGHT 450 nm=blue
Frequency and photon energy are also associated with color, since they are related to wavelength.
The frequency, nu,
HIGHLIGHT nu
Is equal to the speed of light c,
HIGHLIGHT c
divided by the wavelength lambda.
HIGHLIGHT lambda.
Photon energy, E,
HIGHLIGHT E
Is equal to Planck’s constant h
HIGHLIGHT h
Times the frequency nu, or c over lambda
HIGHLIGHT nu and c/lambda
The speed of an electromagnetic wave, on the other hand, is not related to wavelength, frequency, or photon energy.
Its value is 3.00x10^8 meters per second, regardless.
The correct answer is C.
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Frequency and photon energy are also associated with color:  = c/, E = h , or h c/,
The wave speed, c = 3.00x108 m/s, regardless of wavelength.

2. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08