Summary

• Polarization
• Light rays
• Law of reflection

• Law of Reflection applet
• mirror demos
• plane mirrors applet
• virtual images

Example #1

Example #2

• retroreflectors
• candle in water trick





• Spherical mirrors
• center of curvature
• focal point
• three principal rays
• mirror equation

Example #3

Example #4





• Lecture learning outcomes
  A student who masters the topics in this lecture will be able to:
• apply the law of reflection to specular reflection off plane and curved surfaces
• explain the features of a virtual image
• use either a ray diagram or mathematics to predict the location of an image formed by a plane mirror
• draw a ray diagram with three principal rays to predict the image location, orientation, and size for either a convex or a concave spherical mirror
• use algebra to find the object distance d_o, image distance d_i, or focal length f for a spherical mirror when any two of these quantities are given



• Practice:
  Try these additional examples
Example #5

Example #6



• Prepare:
  Read textbook sections 26-5 through 26-7 before the next lecture

klm
What is the shortest mirror in which a 2.0-m tall person can see her entire body?
A. 0.5 m
B. 1.0 m
C. 2.0 m
D. Depends on distance to mirror
Answer














klm
In what location will the image form?

1. A
2. B
3. C
4. D
Answer






















klm
Which ray is correct?
ray A
ray B
ray C
ray D
Answer























klm
A candle is placed 8.0 cm in front of a concave mirror with a radius of curvature of 20 cm. Where is the image?
A. +20 cm
B. −40 cm
C. +2.5 cm
D. −12 cm
Answer















klm
Observer 1 sees an image of a flower at location C. At which location does observer 2 see the image of the flower?

Answer















klm
A 5.00-cm-tall object is placed 12.0 cm in front of a convex mirror with a radius of curvature of 24.0 cm. How tall is the image?
A. 2.50 cm
B. 5.00 cm
C. 7.50 cm
D. 12.0 cm
Answer























 



B. 1.0 m
The ray emerging from the person's foot will strike the mirror at waist level before entering the person's eye. Note the diagram:





















 



4. D
































 



ray C

As it obeys the law of reflection, ray C reflects off the vertex of the mirror as if it were a plane mirror. This is because the slope of the mirror goes to zero at the vertex.















 




B. −40 cm





















 



Location C
The location of the image is determined by the location of the object, not the position of the observer.





















 




A. 2.50 cm