light reflex
1) definition;
When light strikes the surface of an object, it will be reflected by the surface of the object. This phenomenon is called light reflection.
2) Related phenomena:
Reflection in water, flat mirror imaging, seeing unlit objects, periscope, etc.
1, the law of light reflection
1) Normal: Make a straight line perpendicular to the mirror through the incident point. Draw a line with a dotted line! )
2) Incident angle: the angle between the normal and the incident light, represented by the letter I..
3) reflection angle: the angle between the normal and the reflected light, represented by the letter R.
4) the law of light reflection
R=i The reflection angle is equal to the incident angle.
Reflected light, incident light and normal are in the same plane.
Reflected light and incident light are separated on both sides of the normal.
The light path is reversible.
2. Classification of reflection
A. specular reflection: parallel light is directed to the surface of a smooth object, and reflected light is parallel light.
Examples: blackboard reflection, lake reflection, windshield reflection.
B. slow reflection: uneven surfaces will reflect light in all directions.
Example: You can see objects that don't shine in all directions.
Iv. flat mirror imaging T>
1, imaging principle of plane mirror: light reflection.
2, the characteristics of flat mirror imaging:
The straight line between the image and the object formed by the plane mirror is perpendicular to the mirror surface.
The image formed by a flat mirror is equal to the distance from the object to the mirror.
The image formed by a flat mirror is the same size as the object.
The flat mirror looks like an upright virtual oak tree.
Application of plane mirror;
1) imaging (mirror, lake reflection)
2) change the direction of light propagation
3. Convex and concave mirrors
1) convex mirror
It has a divergent effect on light and can expand the field of vision.
For example, the rearview mirror of a car.
The mirror on the corner
2) concave mirror
It has a converging effect on light. Such as flashlight or lamp reflector, solar cooker, etc.