Assume the light wave directed at the paper is white light and the paper contains pigments that absorb the wavelengths of red-orange-yellow-green-blue-indigo -violet. what color will the paper appear to human eyes?
assume the light wave directed at the paper is white light and the paper contains pigments that absorb the wavelengths of red-orange-yellow-green-blue-indigo -violet. what color will the paper appear to human eyes?
a) black
b) brown
c) green
d) white

A) black

Explanation:

Let's begin by explaining that a primary color is one that can not be obtained by mixing any other color.  In this sense, red, green and blue are the primary colors of light (using the additive theory of color), but not the primary colors of the pigments.  

For the case of pigments (using the subtractive color theory) the primary colors are cyan, magenta and yellow. This is because the pigments generally absorb more light than they reflect (they absorb certain wavelengths and reflect others). Therefore, the color that a given object seems to have depends on which parts of the visible electromagnetic spectrum are reflected and which parts are absorbed.  

Hence, according to the subtractive theory, if we join the three primary colors of the pigments, we will obtain the black. Unlike the additive theory of light, in which if we join the three primary colors we will get white light.

This means:

If a paper that absorbs red-orange-yellow-green-blue-indigo-violet is illuminated with white light, the collors our eyes will see is black.

Option A

Explanation:

Humans perceives that color of the object which reflects from an object. White light is composed of all the wavelengths (VIBGYOR (violet, indigo, blue, green, yellow, orange, red)). When white light falls on the paper, the paper absorbs all the wavelengths and reflects none. Thus, the paper would appear to be black to the human eyes.

Therefore, Option A is correct.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y