1. Reflection & Mirrors

2. Reflection The turning back of an electromagnetic wave (light ray) at the surface of a substance. The turning back of an electromagnetic wave (light ray) at the surface of a substance. Depending on how smooth the reflecting surface is, the reflection will either be diffuse or specular. Depending on how smooth the reflecting surface is, the reflection will either be diffuse or specular.

3. Reflections off flat surfaces follow 2 simple rules: Reflections off flat surfaces follow 2 simple rules: angle in (incidence) equals angle out (reflection) angle in (incidence) equals angle out (reflection) angles measured from the surface (normal) angles measured from the surface (normal) Reflection

4. Using the basic rules of reflection, we can create virtual images. Using the basic rules of reflection, we can create virtual images. Virtual images are images formed by light rays that appear to intersect. Virtual images are images formed by light rays that appear to intersect. ex. Looking in a mirror ex. Looking in a mirror Image location can be predicted with “ray diagrams”. Image location can be predicted with “ray diagrams”. Reflection

5. Reflection Ray diagram of mirror image (full length mirror)

6. Two types of curved mirrors 1. Concave mirrors – inwardly curved inner surface that converges incoming light rays. 2. Convex Mirrors – outwardly curved, mirrored surface that diverged incoming light rays.

7. Image location can be predicted with mirror equations. Image location can be predicted with mirror equations. Curved Mirrors Principal axis Center of Curvature ( C ) Focal Length ( f ) Object distance ( p ) h 1/object distance + 1/image distance = 1/focal length 1/p + 1/q = 1/f

8. Curved Mirrors Alternate Mirror Equation: 1/p + 1/q = 2/R 1/object distance + 1/image distance = 2/radius of curvature

9. Concave mirrors… can form BOTH virtual and real images of an object depending on how far the object is placed away from the mirror. can form BOTH virtual and real images of an object depending on how far the object is placed away from the mirror. Real image: an image formed when light rays intersect at a single point. Real image: an image formed when light rays intersect at a single point.

10. Images produced by concave mirrors (virtual or real) will NOT be the same size of our object. Images produced by concave mirrors (virtual or real) will NOT be the same size of our object. They will be magnified (M) They will be magnified (M) magnification = image height = - image distance magnification = image height = - image distance object height object distance object height object distance M = h'/h = - q/p + M = upright and virtual image - M = inverted and real image Concave mirrors

11. Rules for drawing reference lines Ray Line from object Line from mirror to to mirror reflected image to mirror reflected image 1. Parallel to principal Through focal point axis F axis F 2. Through focal point parallel to principal F axis F axis 3. Through the center back along itself through of curvature C C of curvature C C

12. Object distance is greater than the focal length Principal axis Reflecting Surface Ray Diagram fC

13. Object distance is less than the focal length Principal axis Reflecting Surface Ray Diagram fC

14. Convex Mirrors Focal point and center of curvature are located behind the mirror’s surface. Focal point and center of curvature are located behind the mirror’s surface. M is always +, but less than 1 M is always +, but less than 1 Image is always virtual Provide a large field of view Provide a large field of view

15. Convex Mirrors Principal axis fC Reflecting Surface