1. Plane Mirror & Reflection

2. θi θr Normal – imaginary vertical line where the light strikes mirror
Angle of Incidence (θi) – the angle of the incident ray to the normal
Angle of Refection (θr) – the angle of the reflected ray to the normal.
Law of reflection – when light strikes a surface, θi = θr
Mirror
(reflecting surface)
Reflected Ray
Incident Ray
Normal θi θr

3. LEFT- RIGHT REVERSAL
AMBULANCE

4. Da Vinci Writing Materials: plane mirror, paper, pencil
Place the mirror on the paper and hold it there with your hand
While LOOKING into the mirror, try and print you name on the piece of paper so that it appears correctly IN THE MIRROR not on the page
You might need to practice.
Try it with your non-dominant hand
Try writing a secret message to a friend and have them de- code it
Check the accuracy of de-coding the message with the mirror

5. Specular Reflection
Specular Reflection: reflection off of a smooth, shiny surface. Reflected rays are all parallel to each other, and the image is clear.

6. Diffuse Reflection
Diffuse Reflection: reflection off of an irregular or dull surface. Reflected rays are not parallel and the image is fuzzy.

7. ←Specular
Diffuse ↓
DEMO!!
Flash Light & Aluminum Foil

8. Specular vs. Diffuse Reflection
Applications of Specular and Diffuse Reflection:
Countertop surfaces
Furniture or car wax
Glazed vs, unglazed ceramics
Matte vs. Glossy finish on photographs or in paint

9. Virtual Image Created using plane mirrors
An image formed by light coming from an apparent light source; light is not coming from the actual image location
Created using plane mirrors

10. Real Image
An image that can be seen on a screen as a result of light rays actually hitting (arriving) at the image location
Pig Demo

11. Describing an Image
When describing an image you need to consider 4 characteristics known as SALT: S= Size of image (compared to the object: same size, smaller or larger) A= Attitude of image ( which way the image is oriented compared to the object: upright or inverted)

12. Size Attitude Location Type
L= Location of image (infront or behind mirror or lens) T= Type of image (real or virtual)
Size
Attitude
Location
Type
Image
Large Same Small
Upright or Inverted
In front or behind mirror
Virtual or real

13. An image in a plane mirror is always:
S= same size
A= Upright but backwards
L= Behind the mirror (same distance as object in front)
T= Virtual image

14. Creating an Image

16. How to find an Image? Draw the Plane mirror in correct location
Draw object on left side of the mirror
Draw a ray (incidence) through the object to the mirror and reflect the ray off the mirror
Change the angle and draw another ray through the object and reflect it off the mirror
Extend the Reflected rays “through” the mirror until the cross each other
Where the lines cross is where the object is located

17. Example 1 Simple

18. Creating Images

19. Locating Images in a Plane Mirror Lab
Purpose: to test the characteristics of an image in a plane mirror Material: ray box paper plane mirror pencil ruler Procedure: See Ms. Jamieson Observations:

21. Locating Images in a Plane Mirror Lab
Arrow head (cm)
Arrow Tail
(cm)
Length from Object to Mirror
Length from Image to mirror

22. Analysis:
Using your observations describe (SALT) the image that appeared in the plane mirror?
What can you predict about all images in plane mirrors?
Is there a simpler way to locate the image in a plane mirror without using light rays?

23. Plane Mirrors

24. Plane mirror worksheet

25. Applications of Plane Mirrors
Bathroom mirrors to see yourself
Rear View mirrors
Periscopes

26. Applications of Plane Mirrors
Cosmetic mirrors
Rear View mirrors
Periscopes

27. Can you write your name so it looks forward in the mirror?
Leonardo da Vinci used mirror writing when writing in his note book about his inventions. Can you write a mirror message to your neighbour?