Date post: | 30-Dec-2015 |
Category: |
Documents |
Upload: | lawrence-oneill |
View: | 18 times |
Download: | 2 times |
A “Visual” Review
Fuss Physical Science
How do you locate the image in a Curved Mirror Situation.
Pick a point on the object (usually the one furthest from the principal axis), and then draw 2 intersecting rays that obey the following rules:
1. Any ray parallel to the principal axis is reflected through the focus.
2. Any ray through the focus is reflected parallel to the principal axis.
3. Any ray through the center of curvature is reflected back along the incident ray (back along itself)
Concave/Converging
Mirrors
C F
Moving towards the focus, the image is REAL, inverted. It could be smaller, the same size, or larger than the image (depending on the object location)
“OUTSIDE“ the focus
Concave/Converging
Mirrors
C F
NO IMAGE !!!!!! The lines never cross!!!!
“ON” the focus
Concave/Converging Mirrors
C F
“INSIDE” the focus
Moving towards the mirror, the image is VIRTUAL, UPRIGHT, and gets smaller (although the image is ALWAYS larger than the object itself).
Convex/Diverging Mirrors
F C
When an object gets closer to the mirror, its image is VIRTUAL, UPRIGHT, and keeps getting smaller (and the images are always smaller than the object).
C’ F’
Note: All rays want to pass through F, but
none do
Concave mirrors
Convex mirrors
Can make small objects appear larger
Can make large objects appear smaller (see a WIDE view)
Make-up mirrors, shaving mirrors
Security mirrors, Driveway mirrors, Car door mirrors
LENSES
Fuss Physical Science
How do you locate the image formed in a LENSE Situation.
1. Any ray parallel to the principal axis is reflected through the focus.
2. Any ray through the focus is reflected parallel to the principal axis.
3. Any ray through the center of the lens passes directly through the lense following its same path.
Image Formation in CONVERGING Lenses
F’
F
Image Formation in Diverging Lenses
F
F’
Cameras ……
….. and the human eye
BOTH use converging lenses with the object far beyond the focus
and both form INVERTED images.
Film
NOT ON TEST, BUT ON FINAL EXAM!!!!
Magnifying Glasses
2F’ F’ F 2F
Object that you are looking at (under the lens)
Larger, virtual image that you see
Film ProjectorsW
hite screen
The Human EyeCornea: Protective “Window” of
eye
Iris: Colored part that acts like a
camera shutter.
Pupil: Hole in the middle of the
iris.
Lens: has adjustable focal length.
Retina: Where image is formed.
Optic nerve: Sends image to
brain where it is flipped
upside down.
Muscles that “tense” the lens
Furthest Point that the eye can see
clearly
Far Point
Object beyond the far point can’t be focused
clearly on the retina b/c lines cross too soon
Diverging Lens makes the light rays cross further away (on the retina) allowing you
to see a clear image.
Far-Sightedness
Closest Point that the eye can see clearly
Near Point
Object inside the near point can’t be focused
clearly on the retina b/c light rays cross too late
Converging Lens makes the light rays cross sooner,
allowing a clear image to form on the retina
Focus of lens