Transcript Light – Reflection & Mirrors

Light – Reflection & Mirrors
When light hits an object –
The light can be reflected.
The light can be absorbed (opaque).
The light can be transmitted (transparent or
translucent).
2. Kinds of Reflection – Regular reflection occurs when
parallel rays of light hit a smooth surface.
1.
a.
b.
c.
Light – Reflection & Mirrors
3. Diffuse Reflection –occurs when parallel rays
of light hit a bumpy or uneven surface. Most
objects reflect light diffusely!
Light – Reflection & Mirrors
4. Plane Mirrors – Flat mirrors produce an image
that is right – side up and the same size as
the object being reflected called a virtual
image.
5. Virtual Images vs. Real Images –
Right-Side Up
Upside Down
or
or
Upright
Inverted
Light – Reflection & Mirrors
6. Concave Mirrors – Can form either virtual
images or real images.
Light – Reflection & Mirrors
7. Convex Mirrors – Always form virtual images.
Refraction and Lenses
8. Refraction of Light – When light rays enter a
new medium at an angle, the change in speed
causes the light rays to bend or change
direction.
9. Index of Refraction – How much a material
causes a light ray to bend when the light ray
enters that material.
10. Prisms, Rainbows, & Mirages – all are
examples of light being refracted.
Refraction and Lenses
11. Concave Lenses - In this picture the concave
lens forms an image that is smaller, upright
and just in front of the actual object.
Refraction and Lenses
12. Convex Lenses – can produce both virtual and real
images.
Color
13. Color – The color of an object is the Color of
the light it reflects.
14.Objects and White Light – Objects that appear
white reflect all the colors of the visible light
spectrum. Objects that appear black absorb
all the colors of the visible light spectrum.
15.Primary Colors of White Light– Red, Green,
and Blue can be combined to form secondary
colors. Red + Green = Yellow Pg. 584 in Text
Color
16. Complementary Colors of White Light – Any
two colors that combine to form white light.
Ex. Yellow + Blue = White
17. Pigments – Substances that are used to color
other materials. The more pigments that are
combined the darker the mixture looks.
The Human Eye
18. Nearsightedness - The eyeball is too long.
19.Farsightedness – The eyeball is too short.
Both can be corrected by eye glasses or contacts.
Using light
20. Telescopes – use lenses or mirrors to collect
and focus light.
21. Microscopes – use a combination of lenses to
produce and magnify an image.
22. Cameras – use lenses to focus light and
record an image of an object.
Using light
23. Laser – Light Amplification Stimulated Emission
Radiation
Laser Beam – waves of the same wavelength or
color and all the waves are in sync or in step with
each other.
24. Uses of Lasers –
a. To make compact discs [CD’s]
b. Surgery – Soft Tissue
c. Holograms –> 3 –Dimensional photographs by
using the light from a laser.
Using light
25. Optical Fibers – Long, thin strands of glass or plastic
that can carry light for long distances without
allowing the light to fade out .
Total Internal Reflection – Light keeps going even if
the optical fiber is curved or curled up .
Using light
26. Communications – Greatly improved by fiber
optics:
a. Telephone Service
b. Computer Networks
c. Cable T.V. Systems
27. Medicine – Optical Fibers can be used to
examine internal organs without major surgery.