User's Manual

Model No. OS-8459 Teacher’s Guide

Teacher’s Guide

Experiment 1: Color Addition

Note on procedure: Student’s expectation may differ from actual results. Encourage them to carefully

observe the resulting colors and describe them accurately.

Part 1, typical results:

Part 1, answers to questions: 1. Mixing light is not the same as mixing paint. The mixing of colored light

is additive mixing; the mixing of paint is subtractive mixing. 2. In this experiment the mixture of red, green, and

blue does not look pure white to most people. To produce white light, the three colors must be present in a spe-

cific ratios of intensities.

Part 2, typical results:

(Step 4) Under red light, black ink is easier to see than red; red ink appears nearly the same color as white paper.

Part 2: answers to questions: 1. Red ink appears red because it reflects red light and absorbs other colors.

Under blue light, red ink absorbs most of the visible light. 2. Under red light, red ink is difficult to see because

both ink and paper reflect most of the visible light.

Experiment 2: Prism

Notes on procedure: (Step 3) (a) Red, Orange, Yellow, Green and Blue are seen in that order. (b) Blue is

refracted at the largest angle.(c) Blue is predicted to refract at the largest angle because its index of refraction is

largest. (Step 4) When colored rays enter the prism, they do not emerge parallel to each other because of their

differing indices of refraction.

Table 1.1: Results of Colored Light Addition

Colors Added Resulting Color

red + blue + green slightly bluish-white

red + blue pink-purple

red + green yellow-orange

green + blue bluish-green

Table 1.2: Colored Ink Observed Under Colored Light

Color of Light Line Apparent Color of Ink Do they look different? Actual Color of Ink

Blue Light

ABlack

Yes, slightly

Red

BBlack Black

Red Light

CBlack

Yes, slightly

Blue

DBlack Black