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UNIT 8 Light and Optics. mirror. 3. O. 1. 2. S. 4. ConcepTest 35.2a Mirror I. An observer at point O is facing a mirror and observes a light source S . Where does the observer perceive the mirror image of the source to be located?. mirror. 3. O. 1. 2. S. 4.
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mirror 3 O 1 2 S 4 ConcepTest 35.2a Mirror I An observer at point O is facing a mirror and observes a light source S. Where does the observer perceive the mirror image of the source to be located?
mirror 3 O 1 2 S 4 ConcepTest 35.2a Mirror I An observer at point O is facing a mirror and observes a light source S. Where does the observer perceive the mirror image of the source to be located? Trace the light rays from the object to the mirror to the eye. Since the brain assumes that light travels in a straight line, simply extend the rays back behind the mirror to locate the image. Follow-up: What happens when the observer starts moving toward the mirror?
Wednesday February 15th Light and Optics
Wednesday, February 15 TODAY’S AGENDA • Flat Mirrors UPCOMING… • Thurs: Curved Mirrors Concave • Fri: NO School • Mon: Curved Mirrors Convex • Tue: Problem Quiz #1 • Color and Polarization
Chapter 13 Light and Reflection
The Ray Model of Light Light very often travels in straight lines. We represent light using rays, which are straight lines emanating from an object. This is an idealization, but is very useful for geometric optics.
Reflection; Image Formation by a Plane Mirror Law of reflection: the angle of reflection (that the ray makes with the normal to a surface) equals the angle of incidence.
Reflection; Image Formation by a Plane Mirror When light reflects from a rough surface, the law of reflection still holds, but the angle of incidence varies. This is called diffuse reflection.
Reflection; Image Formation by a Plane Mirror With diffuse reflection, your eye sees reflected light at all angles. With specular reflection (from a mirror), your eye must be in the correct position.
Reflection; Image Formation by a Plane Mirror What you see when you look into a plane (flat) mirror is an image, which appears to be behind the mirror. This is called a virtual image, as the light does not go through it. The distance of the image from the mirror is equal to the distance of the object from the mirror.
Reflection; Image Formation by a Plane Mirror Image Image in a Plane Mirror Mirror Object
Reflection; Image Formation by a Plane Mirror f q h Image q f di Image in a Plane Mirror Mirror Object do The image is as far behind the mirror as the object is in front of the mirror.
Instead of a full-length mirror, how short of a mirror will allow you to see your entire body? The mirror needs to be only half your height!
Reflection; Image Formation by a Plane Mirror di Similar Triangles Image hi q f f Image in a Plane Mirror Mirror do Object ho = Image is the same size as the object.