Mirrors 7/24/14 Investigations into Matter and Energy SOL(s): PS.9 c Investigate and Understand Images Formed by Lenses and Mirrors The student will investigate and understand images formed by lenses and mirrors. 1. Predict the characteristics of images formed by lenses and mirrors Predict the characteristics of the images formed by plane, concave, and convex lenses and mirrors. Instructional Objectives: The student will be able to draw the principle ray diagrams for convex and concave lenses and given a labeled diagram identifying the image as real or virtual, erect or inverted, left/right reversed, and magnified, reduced or same size. (Advanced Academic students only) NOTE: The sections below expand as you type in electronic version. Lesson Segment & Time Est. Materials Instructional Sequence Teacher/Student Actions Introduction (Predict, Explain) Small convexmirrors, warmup sheets Predict: Elicit Students Ideas: What will I see as I move this shaving mirror away from my face? Explain why that will happen. Body (Observe) (Explain) Closure (Explain, con t) Student kits with small convex and concave lenses, student worksheets, Smartboard, laptop and LCD projector Computer cart, links to simulations, Explain: Discuss students predictions: Share a few predictions without judging them. Comment on how well supported by the explanation the predictions are. Ask the class which prediction they think is most likely. Observe: Introduce the mirror section of the Optics Files lab by showing students the mirror kit and directing them to the appropriate pages in the lab worksheet. Students, in small groups, will perform various investigations with the mirrors and record their observations (object to mirror distance, characterization of image (real, virtual, upright, inverted, left/right reversed, magnified, reduced). They will make principle ray diagrams for each arrangement on the worksheet. Explain: Project representative mirror and object arrangements using the Smartboard. Have student volunteers put their ray diagrams on the board. Ask for student comments on the ray diagrams. Explain: After putting their ray diagrams on projected images of the mirror and object arrangements, students will run a computer simulation of mirror and object arrangements to verify their principal ray diagrams. Take a concave mirror and move it farther away from your face. Ask students to make predictions (they won t see the mirror very well) on their warm up sheets. Teacher will prepare diagrams of the various mirror arrangements used in the lab for use during discussion. Students will conduct the investigation as directed in the lab manual. At the beginning of the second day, teacher will display the various object and mirror combinations on the Smartboard while students put their ray diagrams on the projected diagrams. Students will work in pairs, using computer simulations to verify their observations from 1
Lesson Segment & Time Est. Total Time = Materials Instructional Sequence Teacher/Student Actions teacher prepared the hands on portion of the ray diagrams for lab. When teacher shows projection, laptop prepared solutions, students and LCD projector will correct their work. 2 days (100 minutes) Assessment Plan: Five question test object and mirror arrangements used in lab Students will draw principle ray diagrams as required by the test items. Teacher will provide the test. Students will draw principle ray diagrams and answer short answer type questions about the diagrams. Attach copies of overheads, activity/laboratory worksheets, assignments, etc. Double-check alignment between lesson objectives, activities, and assessment. 2
Student lab worksheets are found at: Worksheet - http://www.neatscience.com/mirror%20diagram%20worksheet.pdf Rules - http://www.brittonkill.k12.ny.us/welkleyweb/u%2013.5%20optics/u%2013.5%20l2%20optics%20diagrams%20rules.pdf Simulation don t forget to have students enlarge this using Command + http://webphysics.davidson.edu/applets/optics4/default.html Diagrams to be projected as models and for students to complete should be taken from the worksheet above. Typical assessment questions are found on the following pages. 3
Place your object at a distance that is at 0.5f. Make your ray diagram on the diagram below.. f Did your rays intersect on the left side of the mirror? If not, extend the reflected rays. Make them dashed when you extend the lines. Measure d o, d i. Measure the height of the image. Record your answers to the nearest 0.1 cm. Record units on your measurements. d o = d i = Height of image = Type of image = 4
Place your object at a distance that is equal to f. Make your ray diagram on the diagram below.. f Did your rays intersect on the left side of the mirror? If not, extend the reflected rays. Make them dashed when you extend the lines. Name 5
Warm-up Monday, What will I see as I move this shaving mirror away from my face? Explain why that will happen. Tuesday, Wednesday, Thursday, 6
Friday, 7