"Reflection of Light" Light Phenomenon PPT Courseware 4

Description

"Reflection of Light" Light Phenomenon PPT Courseware 4

Knowledge review

What is a light source?

Objects that can emit light on their own are called light sources

how light travels

Light propagates in straight lines in the same homogeneous medium

What is the speed of light

The propagation speed of light in vacuum is 3 × 10 8 m/s

What is one light year?

The distance that light travels in one year is 9.46 × 1015 meters

1. Reflection phenomenon of light

When light hits the surface of an object, it is reflected back by the surface of the object (back to the original propagation medium). This phenomenon is called reflection of light.

We can see non-luminous objects because the light reflected by the objects enters our eyes.

2. The law of reflection of light

Ask a question: What laws follow when light reflection occurs?

Exploration Activity: The Law of Reflection of Light

(1) As shown in the figure, place a white cardboard vertically on the plane mirror, so that a beam of light is close to the cardboard A and shoots towards point O on the mirror surface;

Experiment 2

1. The reflection angle is equal to the incident angle; the reflection angle increases with the incident angle.

2. Reflected light and incident light are separated on both sides of the normal line

1. Among the following idioms, which one can describe the reflection of light ( )

A. Mirage B. Looking at the sky from a well

C.Flower in the mirror D.Immediate effect

2. Among the following statements, which one violates the law of reflection of light ( )

A. The angle of incidence is 0°, and the angle of reflection is also 0°.

B. The incident angle increases by 10°, and the reflection angle also increases by 10°.

C. The incident light ray is close to the normal line, and the reflected light ray is also close to the normal line.

D. The angle of incidence is equal to the angle of reflection

3. The angle between the incident light and the mirror is 40°, then the angle between the incident light and the reflected light is ( )

A.140° B.50°

C.100° D.40°

Draw reflected rays according to the law of light reflection:

Art style:

1. First find the incident point. The perpendicular line passing through the incident point as the reflecting surface is the normal line. The normal line should be drawn as a dotted line.

2. Find the angle of incidence and measure the angle of incidence.

3. Draw an angle through the incident point and the normal line to make the reflection angle equal to the incident angle.

4. Mark the direction of reflection with an arrow.

Standard drawing requirements:

1. You must use a ruler, compass, and pencil for drawing.

2. Use solid lines for light and draw arrows to indicate the direction of light propagation.

3. Draw a dotted line on the normal line

4. A diagonal line should be drawn on the opposite side of the reflective surface

5. Mark the reflection angle r and incident angle i

Which of the following statements is incorrect

A. Specular reflection follows the law of light reflection;

B. Diffuse reflection does not obey the law of light reflection;

C. After the parallel beam is reflected by the plane mirror, it is still a parallel beam;

D. The incident parallel beam in diffuse reflection is no longer a parallel beam after reflection.

When the angle between the incident light and the normal becomes smaller, the reflection angle will be:

A. Get smaller; B. Stay the same; C. Increase.

Regarding the reflection of light, which of the following statements is true

A. When the angle between the incident light and the plane mirror is 200, the reflection angle is also 200

B. When the incident light is close to the normal, the reflected light is also close to the normal.

C. When the incident angle increases by 50, the angle between the reflected light and the incident light also increases by 50.

D. Specular reflection obeys the law of reflection, while diffuse reflection does not obey the law of reflection.

think

1. Why does the projector screen use rough white cloth?

Parallel light is diffusely reflected on rough surfaces, making it visible in all directions.

2. We can see objects that do not emit light from different directions because light strikes the object and _________ occurs.

Application expansion, sublimation and improvement

1. The remote control of the TV can emit an invisible light called infrared, which is used to transmit information and control the TV. Sometimes people can control the TV by pointing the infrared emission window of the TV remote control at the TV or at the wall opposite the TV. This takes advantage of the _______ and _______ phenomena of light.

The movie screen is made relatively rough, causing the light emitted by the video player to _______, allowing viewers from all directions to see the movie.

Polished leather shoes are brighter because light occurs on the surface of the shoe.

2. Regarding the applicable scope of the law of reflection of light, the correct statement is ( )

A. The law of reflection of light only applies to specular reflection

B. Diffuse reflection does not obey the laws of reflection of light

C. Not suitable for vertical illumination

D． The law of reflection of light applies to all reflection phenomena

3. (Multiple choices) One night after the rain, the sky just cleared up. Although the ground was dry, there were still many puddles. In order to avoid stepping into the puddles, the following judgment is correct: ( )

A. When walking in the moonlight, the bright spots on the ground are pools of water.

B. When walking in the moonlight, there is a pool of water in the dark place on the ground.

C. When walking with the moonlight on your back, the bright spots on the ground are pools of water

D. When walking with the moonlight on your back, there is a pool of water in the dark on the ground.

Keywords: light phenomenon teaching courseware, light reflection teaching courseware, People's Education Edition eighth grade physics PPT courseware download, eighth grade physics slide courseware download, light phenomenon PPT courseware download, light reflection PPT courseware download, .PPT format;

For more information about the "Reflection of Light PPT" PPT courseware, please click on the "Reflection of Light PPT Light Phenomenon ppt" tab.

"Reflection of Light" Light PPT download:

"Reflection of Light" Light PPT Download Part One Content: Introduction to New Lesson Through the previous study, we know that light propagates in a straight line. We see that the sun is shining brightly outside the classroom, but there is no trace of sunshine on the blackboard in the classroom. Do you have a way to put the light outside? Sunlight please go to the blackboard..

"Reflection of Light" Light PPT:

"Reflection of Light" Light PPT Part One: Illuminating the Target Turn on the flashlight switch and let the light illuminate the book on the table from top to bottom. How does light illuminate the book? Draw the path of light on the diagram. Without changing the position of the flashlight, stand the book up. At this time,...

"Reflection and Refraction of Light" PPT:

"Reflection and Refraction of Light" PPT Part One Content: Reflection of Light When light hits the surface of an object, part of the light will be reflected back by the surface of the object. The law of reflection of light reflects that the reflected light, incident light and normal are on the same plane Reflected rays and incident rays are separated...

File Info

Update Time: 2024-10-07

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 1 industry PPT template

Preview