reflection and mirrors chapter 23 lesson 2 notes
TRANSCRIPT
Reflection and Mirrors
Chapter 23 Lesson 2 Notes
Law of Reflection
• The law of reflection says that the angle of incidence is equal to the angle of reflection.
Angle of Reflection
Angle of Incidence
Incident R
ay
Reflected Ray
Normal
Flashlight
Diffuse Reflection
• The uneven reflection of light waves from a rough surface is called diffuse reflection.
Regular Reflection
• Regular reflection results from a smooth surface such as a mirror.
Scattering
• Scattering – Light waves traveling in one direction are made to travel in many directions.
– Example – dust in a beam of light
Plane Mirror
• Plane mirror – reflects an actual size image that seems to be behind the mirror due to the way the brain interprets light.
*Looks like a photograph
*Opposite image
*Image seems to come from behind the mirror
Plane Mirror
Concave Mirror
• Concave mirrors cause light rays to converge.
– In a concave mirror, light waves parallel to the optical axis reflect and pass through the focal point.
– Focal length – distance along the optical axis from the center of the mirror to the focal point.
Concave Mirror
– The image formed by a concave mirror depends on the position of an object relative to the focal point.
– Flashlights and headlights form a beam of light when a light source is placed at the mirror’s focal point.
Concave Mirror
Focal Point
Optical Axis
1. If object is farther from the mirror than the focal point Upside Down.
2. If object is closer to the mirror than one focal length Upright and gets smaller as you move closer to the mirror.
If an object is placed outside the focal point its image is real, upside-
down, and enlarged.
If an object is located within the focal length, its
image is virtual, upright, and enlarged
Concave Mirror
Examples of Concave Mirrors
Convex Mirrors
• Convex mirrors cause light rays to diverge.
– The image formed by a convex mirror is upright and smaller than the actual object.
– Convex mirrors are used for security in stores and on the outside rearview mirror of vehicles.
Convex
When you hear “convex” – picture a pregnant belly
The image in a convex mirror is ALWAYS
virtual, upright, and small
Convex Mirrors
Optical Axis
1. Image seems to be behind the mirror.
2. Image is upright and smaller.
Convex Mirrors
Examples of Convex Mirrors