Convex Mirrors
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Transcript Convex Mirrors
Textbook Reference 10.4 (P.431-434)
Convex Mirrors
A mirror with a surface curved outward is a convex
mirror, also called a diverging mirror
A convex mirror spreads out the rays.
Uses for Convex Mirrors
Because convex mirrors allow you to see more than
plane mirrors, they are often used for security in
stores as well as rear-view mirrors in cars.
Images Formed by Convex Mirrors
All images in a convex mirror are virtual.
The reflected light rays never meet and the image
appears to come from behind the mirror.
Images in Convex Mirrors
Rules are similar to those for concave mirror except:
Focus is now called VIRTUAL FOCUS
Both F and C are behind the mirror
Light rays reflecting off a convex mirror diverge (this is why
a convex mirror is called a diverging mirror)
Light rays seem to come from an apparent light source
behind the mirror
Creates virtual images
handout
Light Rays in a Convex Mirrors
RULE: If the incident ray is parallel to the principal
axis, it will reflect as though coming from F.
handout
Light Rays in a Convex Mirrors
RULE: If the incident ray is directed at the focus, it
will reflect as parallel to the principal axis.
handout
Light Rays in a Convex Mirrors
RULE: If the incident ray is directed at the centre of
curvature, it will reflect straight back on itself.
handout
Steps to Locating Images in Convex
Mirrors ... STEP 1
Draw ray 1 from the top of the object.
The incident ray parallel to the principal axis reflects
out, as if it came from the focus.
Extend the reflected ray behind the mirror.
handout
Steps to Locating Images in Convex
Mirrors ... STEP 2
Draw ray 2 from the top of the object.
The incident ray is aimed at the focus, and reflects
parallel to the principal axis.
Extend the reflected ray behind the mirror.
handout
Steps to Locating Images in Convex
Mirrors ... STEP 3
Draw the image where the two rays converge to the
parallel axis.
handout
Steps to Locating Images in Convex
Mirrors ... CHECK
Draw the third ray to check the image.
Incident and reflected rays go through the centre of
curvature. If it intersects, your drawing is correct.
Point of
intersection for
all 3 rays
C
handout
Properties of Images in Convex Mirrors
Image will always be:
Size = SMALLER
Attitude = UPRIGHT
Location = BEHIND THE MIRROR
Type = VIRTUAL
Convex mirrors are useful as security mirrors in stores
and side-view mirrors on vehicles.
Some Uses for Convex & Concave Mirrors
CONVEX mirrors are useful as security mirrors in
stores & side-view mirrors on vehicles.
CONCAVE mirrors are useful as flashlights, telescopes,
car headlights, dental examination lights, and other
applications.
HOMEWORK
TEXTBOOK
P.434 Learning Check #1,3,4
WORKSHEET
“Curved Mirror”