1. By the end of today, IWBAT…
Wednesday, 02/12/15
C-Notes!
TEKS:
P.7E Describe and predict image formation as a consequence of reflection from
a plane mirror and refraction through a thin convex lens.
By the end of today, IWBAT…
Analyze different wave characteristics, including reflection and refraction.
Essential Question:
What are Ray Diagrams?
Topic:
Light & Optics

2. Reflecting And Refracting Light Regular Reflection: Mirrors
Optics: Reflection, Refraction
05/25/2006
Reflecting And Refracting Light Regular Reflection: Mirrors
Send rays straight back
Plane Mirrors: Flat Mirrors
Concave Mirrors: Mirrors that are curved inward.
Send rays inward
Convex Mirrors: Mirrors that are curved outward.
Send rays outward
Lecture 16

3. Reflecting And Refracting Light Regular Reflection: Mirrors
Optics: Reflection, Refraction
05/25/2006
Reflecting And Refracting Light Regular Reflection: Mirrors
Plane Mirrors:
Convex Mirrors:
Concave Mirrors:
Lecture 16

4. Reflecting And Refracting Light Regular Reflection: Mirrors
Optics: Reflection, Refraction
05/25/2006
Reflecting And Refracting Light Regular Reflection: Mirrors
Thicker media refracts light more.
Lecture 16

5. Optics: the overall study of how light behaves
Geometric Optics focuses on the creation of images. It is based on relationships between angles and lines that describe light rays.

6. Reflection and Refraction
A lens is an optical device that is used to bend light in a specific way.
A converging lens bends light so that the light rays come together to a point.
A diverging lens bends light so it spreads light apart instead of coming together.

7. Reflection and Refraction
Mirrors reflect light, while prisms are optical devices that can cause light to change directions.
A prism is a solid piece of glass with flat polished surfaces.

8. Reflection
Images appear in mirrors because of how light is reflected by mirrors.
The incident ray follows the light falling onto the mirror.
The reflected ray follows the light bouncing off the mirror.

9. Reflection
In specular reflection each incident ray bounces off in a single direction.
A surface that is not shiny creates diffuse reflection.
In diffuse reflection, a single ray of light scatters into many directions.

10. Law of Reflection The incident ray strikes the mirror.
The reflected ray bounces off.
The angle of incidence equals the angle of reflection.

11. Law of Reflection
30o
A light ray is incident on a plane mirror with a 30 degree angle of incidence.
Sketch the incident and reflected rays and determine the angle of reflection.
1) You are asked for a ray diagram and the angle of reflection.
2) You are given the angle of incidence.
3) The law of reflection states the angle of reflection equals the angle of incidence.
4) The angle of reflection is 30°.

12. Optics: Reflection, Refraction
05/25/2006
Reflection
We describe the path of light as straight-line rays
Reflection off a flat surface follows a simple rule:
angle in (incidence) equals angle out (reflection)
angles measured from surface “normal” (perpendicular)
surface normal
same
angle
incident ray
exit ray
reflected ray
Lecture 16

13. Reflection Vocabulary
Real Image –
Image is made from “real” light rays that converge at a real focal point so the image is REAL
Can be projected onto a screen because light actually passes through the point where the image appears
Always inverted

14. Reflection Vocabulary
Virtual Image–
“Not Real” because it cannot be projected
Image only seems to be there!