On the bright side, some places are bright and some places are dark, so light will be reflected, and there is reflective physics. Because light travels in a straight line, it will be blocked, and light energy can be absorbed and converted into heat energy. Conditions of light reflection: light source and reflector.

Step 2 ask questions

Question 1: How is the light reflected?

Question 2: Is there any regularity in the reflection of light?

3. Guess

This may be related to the incident angle of two kinds of light, which are called incident light and reflected light.

4. Experimental ideas

By changing the angle of light incident angle, the same light source can only change the angle of incident angle and observe the angle of reflection angle.

Step 5 experiment

1. according to figure a, use a laser pen to shoot a beam of light along the plane of the folding board, observe the incident light and reflected light, and record the incident angle and reflection angle; Fill in the data in the form.

2. Repeat the above experiment by changing the direction (incident angle) of incident light, and record the table.

6. Record the experimental results

? 1 2 ? three

Incident light? 90 30 ? 20

Reflective? 90 30 ? 20

7. Experimental conclusion In the same homogeneous medium, the normal lines of incident light and reflected light are in the same plane.

Paper: With a small mirror, outdoor sunlight can shine into the room, and the sparkling water surface on the pond can be seen during the day, which is related to the reflection of light. What is the reflection of light? When light strikes the surface of an object, it will be reflected back by the surface of the object. This phenomenon is called light reflection.

In the phenomenon of reflection, the light projected on an object is called incident light, the projection point between incident light and the object surface is called incident point, the light returning from the object surface is called reflected light, the straight line passing through the incident point and perpendicular to the object surface is called normal line, the normal line is in the middle between incident light and reflected light, the included angle between hair line and incident light is called incident angle, and the included angle between reflected light and normal line is called reflection angle. The angle of incidence and the angle of reflection are exactly the same. There are two kinds of light reflection, one is specular reflection and the other is diffuse reflection. Parallel beams are projected on a smooth surface, such as a mirror or calm water, and the reflected beams are still parallel. This reflection is specular. For example, turning on the laser light will be reflected by the mirror, and the speed of light will be reflected to our eyes, not to other people's eyes. But after the rough object is reflected, the speed of light is not parallel, but will shoot in all directions, which is diffuse reflection. For example, in class, what the teacher writes on the blackboard can be seen by everyone, not just people in a certain area.

There is a law of light reflection. "When light is reflected, the reflected light and the incident light are in the same plane as the normal, and the reflected light and the incident light are located on both sides of the normal respectively, and the reflection angle is equal to the incident angle." This conclusion is the law of light reflection. The incident angle and reflection angle of diffuse reflection are irregular.