Colors of Light (Worksheet)

Objectives

In this activity, you should be able to

1. make a color spectrum wheel;

2. explore the characteristics of color lights; and

3. observe how primary colors combine to form other colors.

Materials Needed

·         Color Spectrum Wheel Pattern Cardboard or illustration board

·         white screen

·         plastic filters (green, blue and red)

·         3 pieces of high intensity flashlights

·         button fastener

·         glue or paste

Procedure

Part 1: Color Wheel

1. Cut the two art files that make up the wheel as shown below.

2. Cut along the lines drawn on the top wheel. Cut the 2 sides as shown. The small window near the center of the wheel should be completely cut out and removed.

3. Punch a hole at the center of the two wheels. You may use a button fastener to secure the two wheels together one on top of the other, but they should be free to rotate relative to each other.

4. When you see a region of the Color spectrum show up in the open window and the “W, F, E” that correspond to that region showing up under the flaps then you know that you have done it right.

Part 2: Characteristics of Light

1. Try out your Color Spectrum Wheel by positioning the inner most of the flaps on COLOR SPECTRUM. This will simultaneously position the other flaps to ENERGY, WAVELENGTH and FREQUENCY.

2. Turn the upper wheel and observe the combinations.

3. Fill in the table below with the corresponding combinations you have observed using your Spectrum Wheel.

Characteristics of Color Lights

Color Spectrum	Energy (eV)	Frequency (THz)	Wavelength (nm)	Frequency X wavelength (m/s)
Red
Orange
Yellow
Green
Blue
Violet

4. You will need to convert the equivalents of frequencies to Hz and the equivalent wavelengths to meters. Note that terra (T) is a prefix for 10¹⁴ while nano (n) is a prefix equivalent to 10^-9 .

Questions:

1. Which color registers the highest frequency? shortest wavelength?

2. Which color registers the lowest frequency? longest wavelength?

3. What do you observe with the wavelength and frequency of the different colors?

4. What did you observe with the product of wavelength and frequency for each color? What is the significance of this value?

5. What can you say about the speed of the different colors of light in air?

6. Give a plausible explanation as to why white light separate into different colors.