"Color of Objects" Light Phenomenon PPT Courseware 2

Description

"Color of Objects" Light Phenomenon PPT Courseware 2

Review and consolidate:

1.Law of reflection of light

2. The law of refraction of light

3. Characteristics of plane mirror imaging

4. The difference between real image and virtual image

directional signs

1. Understand the phenomenon of dispersion and know that the three primary colors of light and the three primary colors of pigments are different

2. Explore the mixing of shades and pigments

3. Understand the relationship between the color and light of objects 1

Self-study guide:

Read the textbook and answer the following questions:

1. Who invented the dispersion of light and what are the main experimental instruments used?

2. What is the phenomenon after sunlight occurs?

3. What are the three primary colors of light?

4. What determines the colors of transparent objects and opaque objects?

1. Dispersion

The light from the sun illuminates the earth and makes all things shine. Before the 17th century, people always believed that white was the simplest color. It wasn't until 1666 that the British physicist Isaac Newton used a glass prism to disperse the sun, and the mystery of the color of light was revealed.

Let a beam of sunlight shine on a prism. What happens to the light emerging from the prism?

Red light in sunlight has the smallest deflection, while violet light has the largest deflection.

in conclusion

Sunlight (white light) is not monochromatic light, but is a mixture of various colored lights.

concept

After sunlight passes through a prism, it is decomposed into light of various colors. This phenomenon is called dispersion of light.

Sunlight (white light) is a mixture of seven monochromatic lights: red, orange, yellow, green, blue, indigo, and violet.

2. Mixing of colors and lights

Red, green, and blue are called the three primary colors of light. Different colors can be mixed by using these three kinds of light.

What color will it be if you mix any two colors of red, green and blue?

red + green = yellow

red + blue = magenta

Green + blue = cyan (indigo)

red+green+blue=white

3. Color of object

We know the dispersion of light, so why do objects have various colors?

(1) Color of transparent objects

The color of a transparent object is determined by the colored light passing through it.

practise

Red cellophane can only pass _____ light

Green cellophane can only pass _____ light

Blue cellophane can only pass _____ light

(2) Color of opaque objects

The color of an opaque object is determined by the colored light it reflects;

An opaque object can only reflect light of its own color.

Stick the green paper on the white screen so that only the areas on the screen illuminated by green light are bright.

(3) The three primary colors of pigments are magenta, yellow, and cyan.

They can produce different colors in different proportions.

magenta+�=red

�+blue=green

Magenta + Yellow + Blue = Black

When painting, you can create most colors by using the three primary colors.

Consolidation exercises

1. After sunlight passes through a prism, it will be decomposed into light of various colors. If a white screen is used to receive it, the order of colors on the white screen is red, _____, _____, ______, ______, ______, _____. this means________________.

2. The color of a color TV is produced by the electron gun in the TV shooting onto the phosphor on the inside of the screen. According to the mixing rules of color light, only three colors of electron guns, ______, ______, and _______, are needed in the TV. Can be matched with a variety of brilliant colors.

Exercise: 1. The color of a colored transparent object is determined by its _____, and the color of a colored opaque object is determined by its _____.

2. The color of an object that can absorb all colors of light is _____.

3. The color of an object that can reflect light of various colors is: ( )

A. White. B. Colorless.

C. Black. D. This color does not exist.

4. When a beam of light shines on a piece of paper and the paper appears red, then the relationship between this beam of light and the paper is: ( )

A. Red light, white paper B. White light, red paper

C. Red light, red paper D. The above situations are possible.

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For more information about the "Color of Light Phenomena Objects" PPT courseware, please click the "Color of Light Phenomena Objects" ppt tag.

"Color of Objects" Light Phenomenon PPT Courseware 3:

"Color of Objects" Light Phenomenon PPT Courseware 3 1. Dispersion 1. The phenomenon that sunlight is decomposed into seven colors of light after passing through a prism is called dispersion of light. 2. White light is a mixture of seven monochromatic lights: red, orange, yellow, green, blue, indigo and violet. Exchange and discussion 1.Light..

"Color of Objects" PPT courseware on light phenomena:

"The Color of Objects" Light Phenomenon PPT Courseware [Experience] Dispersion of Light Activity 1: Prepare water, a container, a plane mirror, and a paper screen. Place the device as shown in the figure. Adjust the mirror angle to refract sunlight onto the white paper screen. Observe the light on the paper screen. color. Activity 2: Put the CD in the sun..

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Update Time: 2024-10-17

This template belongs to Physics courseware Beijing Normal University eighth grade physics volume one industry PPT template

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