3. TWO KIND OF REFLECTIONS
The reflection of light can be roughly categorized into two types of reflection:
specular reflection is defined as light reflected from a smooth surface at a
definite angle, and diffuse reflection, which is produced by rough surfaces
that tend to reflect light in all directions
4. TWO KIND OF REFLECTIONS
Specular reflection
Diffuse reflection
5. WHEN THE DIFFUSE REFLECTION OCCUR?
It is hard to believe, but you have to know that all objects reflect
rays, but those which surface is not flat give diffuse reflection and
become indirect-lighting device. Yes, your hand also reflects and diffuse
much of the light it receives. Its surface is rough, so rays have different
angles of incidence and different angles of reflection and are diffused.
This phenomenon allows us to see objects which are not the sources of
light.
6. HOW THE MIRROR WORK?
h
Images are classified as real or virtual. A real image is formed when
light rays pass through and diverge from the image point; a virtual
image is formed when the light rays do not pass through the image
point but appear to diverge from that point.
Lateral magnification
h’
7. HOW THE MIRROR WORK?
A flat mirror produces an image that
has an apparent left–right reversal.
You can see this reversal by standing
in front of a mirror and raising your
right hand. The image you see raises
its left hand. Likewise, your hair
appears to be parted on the side
opposite your real part, and a mole on
your right cheek appears to be on your
left cheek.
8. SPHERICAL MIRROR
A spherical mirror, as its name implies, has the shape of a section of a sphere.
This type of mirror focuses incoming parallel rays to a point, as demonstrated by
the colored light rays.
9. CONCAVE MIRROR
(a) A concave mirror of radius R. The center of curvature C is located on the
principal axis. (b) A point object placed at O in front of a concave spherical
mirror of radius R, where O is any point on the principal axis farther than R
from the mirror surface, forms a real image at I. If the rays diverge from O at
small angles, they all re.ect through the same image point.
11. ESTABLISHMENT OF SHADOWS BY THIN LENSES
SAME PRINCIPLE, SUCH AS FORMATION OF SHADOWS ON THE EVENTS
OF LIGHT REFLECTION, USING A SPECIAL LIGHT RULES:
SPECIAL BEAM TO CONVERGING LENS (A POSITIVE LENS);
• RAYS COME PARALLEL TO THE MAIN AXIS WILL BE REFRACTED
TOWARD THE FOCAL POINT (F).
• RAYS COME TO THE POINT OF FOCUS (F) WOULD BE REFRACTED
PARALLEL TO THE MAIN AXIS.
• RAYS TOWARD THE CENTER OF CURVATURE (P) WILL BE
FORWARDED.
+
F
F
p
12. ESTABLISHMENT OF SHADOWS BY THIN LENSES
RAYS SPECIAL FOR DIVERGENT THIN LENSES (NEGATIVE LENSES);
• RAYS COME PARALLEL TO THE MAIN AXIS WILL BE REFRACTED AS
IF FROM THE POINT OF FOCUS (F).
• RAYS COME TO THE POINT OF FOCUS (F) WOULD BE REFRACTED
PARALLEL TO THE MAIN AXIS.
• RAYS TOWARD THE CENTER OF CURVATURE (P) WILL BE
FORWARDED.
-
F
F
p
13. ESTABLISHMENT OF SHADOWS BY THIN LENSES
BANYANGAN FORMATION BY THE LENS ISSUE WOULD BE
INTERESTING IF DONE THE MERGER OF TWO LENSES.
NOTE:
COAT OF LENS IS USUALLY USED A LINE THAT IS MARKED
"+" OR "-".
IMAGE FORMATION BY LENSES OF POSITIVE-POSITIVE :
+
F1
Benda
Nyata
+
F1
Bayangan
Nyata
Terbalik
F2
F2
Bayangan
Nyata
Tegak
14. THANK YOU
CREATED BY:
RAHMAWATI TH. DIAMANTI
09 312 405
KELAS C
JURUSAN FISIKA
FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM
UNIVERSITAS NEGERI MANADO
2010