20.2. Concave and Convex Mirrors http://www.ck12.org
FIGURE 20.11
Again, with a bit of geometry, we can demonstrate that the object distancedo, the image distancedi, and the focal
lengthfare related by the mirror equation:
1
do+
1
di=1
fConcave mirror-objects placed in front of the focal point
When an object is placed closer to the concave mirror than the focal point, a virtual image is formed. The same
principal rays are used to construct the diagram, but the construction is not quite as straightforward as before.
Figure20.12 shows the ray diagram for this situation.
FIGURE 20.12
An object placed in front of the focal
point.