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Science 8 Reflection in PLANE (Flat) Mirrors
What is specular reflection?
REFLECTION FROM A SMOOTH SURFACE THAT CREATES AN IMAGE (EX. mirrors, in
still water)
What is diffuse reflection?
REFLECTION FROM A ROUGH SURFACE THAT DOES NOT CREATE AN IMAGE, BUT
SCATTERS LIGHT (Ex. frosted glass, paper)
What is a PLANE MIRROR?
A regular flat mirror
Describe the image you see in a plane mirror:
Size: The image is the SAME SIZE as the object.
Attitude: The image is UPRIGHT (but left and right are reversed)
Location: The image is the same distance, but it appears BEHIND the mirror
Type:
The image is VIRTUAL.
The Laws of Reflection:
1st : The angle of INCIDENCE is equal to the angle of REFLECTION
2nd : The angle of incidence, angle of reflection and the normal line all occur in a PLANE
(flat surface)
point of incidence
Science 8 Curved Mirrors
Concave
Convex
Focus or focal point
Imaginary Focus
It’s also called a converging mirror.
It’s also called a diverging mirror.
The reflected rays come together and pass Reflected rays spread out.
through a focus.
“Spread out” means diverge.
“Come together” means converge.
There is no real focus in a convex (diverging)
The point where the reflected rays meet is mirror. It appears that the focal point is behind
called the focus.
the mirror.
Images depend on where the object is
located
Images are ALWAYS
 Smaller OR larger
 smaller
 Upright OR inverted
 upright
 Closer OR farther
 closer
 Real OR virtual
 virtual
Concave
Convex
Examples:
Examples:
Make – up mirrors – within one focal length, a
face is upright and larger
Security mirrors in stores give a wide, upright
view of people
Dentists’ mirrors
Give an enlarged, upright
image of teeth
Reflectors in flashlights – focus light to create a
narrower, more concentrated beam
Telescope mirrors – large mirrors collect and
concentrate light to make stars appear
brighter
Passenger - side mirrors on cars give the driver
a wider view, but distorts distance (“Objects
are closer than they appear)