1. J.M. Gabrielse

2. Outline Reflection Mirrors Plane mirrors Spherical mirrors Concave mirrors Convex mirrors Refraction Lenses Concave lenses Convex lenses

3. J.M. Gabrielse A ray of light is an extremely narrow beam of light.

4. J.M. Gabrielse All visible objects emit or reflect light rays in all directions.

5. J.M. Gabrielse Our eyes detect light rays.

6. J.M. Gabrielse We see images when light rays converge in our eyes. converge: come together

7. J.M. Gabrielse Mirrors object image It is possible to see images in mirrors.

8. J.M. Gabrielse

9. Mirrors reflect light rays.

10. J.M. Gabrielse Plane Mirrors (flat mirrors) How do we see images in mirrors?

11. J.M. Gabrielse Plane Mirrors (flat mirrors) objectimage Light reflected off the mirror converges to form an image in the eye. How do we see images in mirrors?

12. J.M. Gabrielse Plane Mirrors (flat mirrors) objectimage Light reflected off the mirror converges to form an image in the eye. The eye perceives light rays as if they came through the mirror. Imaginary light rays extended behind mirrors are called sight lines. How do we see images in mirrors?

13. J.M. Gabrielse Plane Mirrors (flat mirrors) objec t imag e Light reflected off the mirror converges to form an image in the eye. The eye perceives light rays as if they came through the mirror. Imaginary light rays extended behind mirrors are called sight lines. The image is virtual since it is formed by imaginary sight lines, not real light rays. How do we see images in mirrors?

14. J.M. Gabrielse Spherical Mirrors (concave & convex)

15. J.M. Gabrielse

36. Lensmaker’s Equation ƒ = focal length d o = object distance d i = image distance if distance is negative the image is behind the mirror

37. J.M. Gabrielse Magnification Equation m = magnification h i = image height h o = object height If height is negative the image is upside down if the magnification is negative the image is inverted (upside down)

38. J.M. Gabrielse

39. Lenses The first telescope, designed and built by Galileo, used lenses to focus light from faraway objects, into Galileo’s eye. His telescope consisted of a concave lens and a convex lens. Light rays are always refracted (bent) towards the thickest part of the lens. convex lens concave lens light from object

40. J.M. Gabrielse

49. Convex Lenses Convex lenses are thicker in the middle and focus light rays to a focal point in front of the lens. The focal length of the lens is the distance between the center of the lens and the point where the light rays are focused.

50. J.M. Gabrielse