3. Any incoming ray parallel to the principal axis will be reflected back as if it were coming from the focal point (Fig. 13.14).
F C
FIG. 13.14
4. Any incoming ray directed towards C will be reflected back along its original path (Fig. 13.15).
C
FIG. 13.15 Images in a convex mirror
The type of image produced by a convex mirror is always the same, no matter where the object is placed (Fig. 13.16).
You should note the following: • All images produced in a convex mirror are virtual and upright. • As an object is moved closer to a convex mirror, the image increases in size. However, the image is always diminished and will therefore never match the object size.
Optics formulae for convex mirrors
General optics formula 1
___ u + 1
___ v = 1
___ f
u = object distance (m), v = image distance (m), f = focal length (m) For convex mirrors:
• u is positive • v is always negative (since all images in convex mirrors are virtual) • f is always negative.
