Chapter 13 Physical Science Review
List three different uses for a laser.
1. CD player 2. surgical tools 3. communication 4. CAT TOYS
Must a transparent material be colorless? Explain.
No, it could be a filter so that you see one color of light but are still able to see objects through it.
What color are the longest wave lengths of visible light?
red waves
Why is an apple red?
It only reflects red light and absorbs all others.
What is the difference between a hologram and a photo?
Holograms record the direction of light and are 3-D and made with lasers while photos record the absence of light and are two dimensional.
What does LASER stand for?
L-ight A-mplification by S-timulated E- mission of R-adiation
Why would you want sunglasses with polarized lenses?
Most reflected light is seen as a glare and it blocks out the glarre.
Green light shines on a red piece of paper. What color is seen? Explain what happens to each of the primary colors.
Since the red paper reflects only red light, it would absorb the green light being shine in it and would not reflect anything since there is no red light, making it appear dark or black.
State the Law of Reflection:
The angle at which a light wave strikes a surface is the same angle at which it is reflected.
Explain why light bends as it passes from air into glass at an angle.
The glass and air have different indexes of refraction, thus causing the refraction of light as it slows down to enter the glass.
Which type of lights are incandescent bulbs filled with a gas to make the filament last longer?
Tungsten-Halogen Lights
Explain how an incandescent light bulbs work.
a piece of metal (filament) is heated until it glows
List two advantages of using a fluorescent light bulb instead of incandescent light bulb:
a. They use 1/5 the energy to produce the same light. b. Reduce burning of fossil fuels. c. Uses less electricity.
On what two things do total internal reflection rely?
a. light must travel slower in the first medium b. must strike at an angle greater than the critical angle
translucent
allows some light to pass through examples:light covers
mirage
an image of a distant object produced by the refraction of light through air layer of different densities
What color is produced by blending the three primary pigments?
black
What color is obtained when the three primary colors of pigment are mixed? Explain.
black, because it is subtractive
pigment
colored material that is used to change the color of other substances; absorbs some colors and reflects others
What is a photographic image of a 3-D object made without a lens?
hologram
What type of light is produced by heat?
incandescent
What are the primary pigment colors?
magenta, cyan, yellow
What gas is commonly used in lighting devices?
neon
Most of the light is absorbed or reflected when light strikes what type of material?
opaque
In what type of light do waves vibrate in only one direction?
polarized
What are the primary colors of light?
red, green, blue
What is it called when a wave strikes an object and bounces off?
reflection
Eyeglasses, binoculars, and cameras take advantage of what principle?
refraction
What do we call reflection of light waves from a smooth surface?
regular reflection
On what does light focus when it enters the eye/
retina
On what do optical fibers rely on for their efficiency?
total internal reflection
transparent
transmit almost all light through them examples: window
How often is light refracted in a prism?
twice, once when it enters and once when it exits
What color is produced by blending the three primary colors of light?
white
What color is obtained when the three primary colors of light are mixed? Explain.
white, because it is additive
