1. Ray diagrams, lens equation Thursday, April 21, 2016

2. Unit 12: Optics Thursday, 4/21 Upcoming dates:  Thursday, 4/21 – Last day to re-test on Waves  Wednesday, 4/27 - EM Spectrum/Optics quiz  Friday, 4/29 – EM Spectrum/Optics test all missing EM Spectrum/Optics work is due (missing work is a zero after you test)  Monday, 5/9 – Atomic Physics test all missing Atomic physics work is due (missing work is a zero after you test)  Tuesday, 5/17 – Rube Goldberg Project due (test grade)  Monday, 5/23 – Bottle Rocket launch day  Tuesday, 5/31 – Exam review due (it is 30% of your exam grade) Pick up a sheet of white paper and DO NOT WRITE ON IT! Draw the mirrors below and label them (concave, convex)

3. Warm-up answer

4. Introduction to lenses  On the back table you will find two different shaped lenses.  Place the lenses in front of the light source and observe what the light ray does.  You will trace the the incoming and outgoing (show me your rays before tracing).  Trace the rays on the paper provided (we will be adding notes to your diagrams.

5. CNs

6. Convex Lens

7. Concave Lens

8. Synthesizing what we know  For two minutes you will write about the how light rays behave (reflection and refraction) and what role the shape of lenses have on the direction of the outgoing light ray.

9. Ray Diagrams  Diagraming the light rays from an object allow us to predict the image we see.  Location of the image  Real or virtual  Orientation; upright or inverted  Size; enlarged, same size, reduced)  We will do this for convex lenses only!

10. Setting up the principal axis

11. Rules for Drawing Ray Diagrams Note: the point where the lines intersect is the image location. Darken in that point (point becomes the tip of the arrow)

12. Example 1

13. Example 2

14. Example 3

15. Example 4

16. Example 5

17. CNs – Lens Equation Focal length (cm) Distance of object (cm) Distance of image (cm)

18. CNs – Magnification Equation Object magnification (cm) Height of image (cm) Distance of image (cm) Distance of Object (cm) Height of object (cm)

19. Practice questions

20. Cool Down  If the magnification is a negative number what does it tell you about the size of the image compared to the actual size of the object?