1. Mirror Equation Ray diagrams are useful for determining the general location and size of the image formed by a mirror. However, the mirror equation and magnification equation give a more accurate mathematical description of the image

2. Mirror Equation f = focal length of the mirror d o = object distance (distance between the object and the mirror. d i = the image distance (distance between the image and the mirror) m = magnification of the mirror

3. Mirror Equation

4. Magnification Equation

5. Sign Conventions for Spherical Mirrors Focal length f is + for a concave mirror f is – for a convex mirror Object distance d o is + if obj is real (in front of mirror) d o is – if obj is virtual (behind the mirror)

6. Sign Conventions for Spherical Mirrors Image distance d i is + if image is real (in front of mirror) d i is – if image is virtual (behind the mirror) Magnification m is + if the image is upright (w/r/t object) m is – if the image is inverted (w/r/t obj)

7. Example 1 A 2.0 cm high object is placed 7.10cm from a concave mirror whose radius of curvature is 10.20 cm. A) find the location of the image B) find the size of the image

8. Example 1 A 2.0 cm high object is placed 7.10cm from a concave mirror whose radius of curvature is 10.20 cm. f=1/2R = ½(10.20)=5.10cm, so the object is located between the center of curvature and the focal point.

9. Example 1