FLAT AND CONCAVE MIRRORS...
For a flat mirror the object and image
distances, p and q, are the same, and the object and image sizes
are the same, so the magnification is 1.0.
For the concave mirror, the focal distance f
= R/2 and the object and image distances are related by (1/p)
+
(1/q) = (1/f).
Sign rule: p is positive if the
object is in front, q is positive if the image is in
front, and f is positive if the focus is in front.
Because light is actually brought to a
focus by a concave mirror, the image it forms is said to
be "real," unlike the image formed by a flat mirror. The
image seen in a flat mirror is called "virtual," because
the light seen does not come from the point in space the
image appears to occupy.
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