1. “Camera obscura Lab Report day” 9.9.11. Wiki:Notes and worksheets and some keys (see “teacher websites”) Hand in Worksheet “finding the diameter of the sun” by 3 PM today into the “Bin” Camera Obscura Problem worksheet is HW Syllabus coming on Monday!!

2. Use a pinhole in a card to find the diameter of the sun Change km to meters Change cm to meters Find diameter of the sun (height of the object) h i = - d i h o d o hihi didi dodo hoho

3. Skip #3 Change all units to meters Height of image Distance to image Distance to the object = distance to the sun Height of image (-) because it is real hihi didi h i = - d i h o d o

4. Problems Work problems for both sets of data on the back –Show your work –Equation –Substitution –Answer –Label

5. FYI: 1 meter = 100 cm 1 km = 1000 meters Magnification –No Label on Magnification –Real image the magnification is a negative –Magnification is < 1 if the image is smaller –Use: M = h i or M = -d i h o d o

6. Hi =??? Ho =190 cm Di = 6.2 cm Do= 438 cm M = h i = - d i h o d o The height should be (-) because it is a real image Labels should all be the same The first answer is -2.69 cm The second answer is -0.014 h i = - d i h o d o

7. Camera Obscura Lab Report Take your data from the 3 objects you viewed in the Camera obscura and enter in the data table For this lab, Pringles can is 23 cm long Height of the image (-) Height of the Object is (+) Magnification is (-)

8. hi ho di do M = h i = - d i h o d o Rays are straight lines of light Notice that the rays from each edge of the object cross exactly at the pinhole when it is very small Be sure to draw in the image in the diagrams!!

9. hi ho di do M = h i = - d i h o d o What happens to the image when the object is closer to the pinhole?

10. hi ho di do M = h i = - d i h o d o When the pinhole is larger, More rays enter the pinhole from each spot on the object, What effect does that have on the image? Would the image be more or less clear? Would the image be more or less bright?

11. Syllabus on Monday! Camera Obscura lab is due Tuesday at 3 PM, If you are finished early, you may place your lab with your name and hour in the “BIN” You will have time to ask questions on Monday, but not on Tuesday during classt ime. Camera Obscura Problems worksheet is Homework (Write: HW ) on top of paper You may engrave your name on your calculator