1. Chapter 5

2. Early understanding of light Issac Newton (particle theory of light) – Thought light was made up of tiny particles – Extremely fast moving – Traveled in a perfectly straight line – Hit your eye and make an image

3. Ray model of light Represented as a straight line (ray) – Shows the direction the light is traveling

4. Transparent objects Transparent material is “clear” meaning we can see right through it This material allows light to pass through it freely Only a small amount of light is absorbed and reflected – Air, water, window glass

5. Translucent objects Translucent materials let most light through Light is scattered in all directions Cannot see through it distinctly – Bathroom windows (light in but keep privacy)

6. Opaque objects Completely prevent light from passing through All light reflects and/or refracts of the object

7. Shadows Tell us that light travels in straight lines – Rectilinear Propagation Simplified ray diagram (page 175) – Lower the sun, the longer your shadow

8. Light can be reflected Specular reflection: reflection off of a flat surface – Produces an image of the surroundings Diffuse reflection: reflection off of a rough surface – Does not produce a clear image, allows you to see the surface – Any books you read use this type of reflection

9. Law of reflection Think of water waves – They hit a barrier straight on, they bounce straight backwards – They hit at an angle and bounce off at the exact same angle Ray diagram:

10. Ray Diagrams Important facts to learn Incident rays: incoming rays Reflected rays: ray that bounces off the barrier Normal: perpendicular to the barrier, right where the reflected ray hits Angle of incidence: angle between the incident ray and the normal Angle of reflection: angle between the reflected ray and the normal Angle of incidence = Angle of reflection

11. Light can be Refracted Refraction is the bending of a wave – When the wave transfers from one medium to another it bends or refracts – Speed of wave changes in different mediums See figure 5.12, page 179

12. Direction of refracted ray The more the wave is slowed, the closer the ray gets to the normal Rays travel slower in denser objects, faster in less dense mediums Fastest in a vacuum.

13. The direction of Refraction When light travels from a less dense to a more dense medium the ray bends towards the normal When light travels from a more dense to a less dense medium the ray bends away the normal

14. Refraction Effects

15. Terms to Know

16. Questions Review page 182 and answer questions 1 and 2.

17. 5.2 and 5.3 5.2 Images in Plane Mirrors 5.3 Images in Curved Mirrors

18. Types of Mirrors: 1.Plane Mirrors - Flat, smooth mirror

19. Characteristics of images using Plane Mirrors 1.Image size is equal to object size 2.Image distance is equal to object distance 3.Image is upright 4.Image is virtual

20. Plane Mirror

21. Examples of Plane Mirrors Bathroom Dentist mirror Telescope

22. Ray Diagrams….parts to know

23. 2. Concave Mirrors Have a reflecting surface that curves inward like the inside of a bowl

24. Characteristics of images using Concave Mirrors 1.Can be smaller or larger or the same size 2.Can be upright or inverted 3.Can be virtual or actual

25. Concave mirrors

26. Examples of Concave Mirrors 1.Metal spoon 2.Spotlights 3.Overhead projectors 4.Flashlights 5.Car headlights 6.Lighthouses 7.Satellite dishes

27. 3. Convex mirrors Curved outward like the outside of a bowl

28. Characteristics of images using Convex Mirrors 1.Image is smaller than the object 2.Image distance is smaller than the object distance 3.Image is upright 4.Image is virtual

29. Examples of Convex Mirrors 1.Safety mirrors in front of bus 2.Side view mirrors of vehicles