18.3 behavior of light 18.3 key concepts what three types of materials affect the behavior of light?...
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18.3 Behavior of Light
18.3 Key Concepts• What three types of
materials affect the
behavior of light?
• How does light behave
when it enters a new
medium?
18.3 Behavior of Light
Without light _______________ is visible.
You can see reef animals through water because light ___________ through the water between the reef and your _________.
nothing
passes
eyes
18.3 Behavior of Light
Light and Materials
•How light behaves when it strikes an object depends on many factors, including the __________________ the object is made of…
• Materials can be…• ______________________• ______________________• ______________________
material
transparent
translucent
opaque
18.3 Behavior of Light
A transparent material _____________ light, which means it allows __________ of the light that strikes it to pass through it.
.
Light and Materials
The water where the
fish and coral live is
transparent.
transmitsmost
18.3 Behavior of Light
.
Light and Materials
While riding on a bus, you can see buildings and trees outside because the bus ______________ are transparent.windows
18.3 Behavior of Light
A translucent material ____________ light.
As a result, the objects you see through it look ____________ or may lack _______________; as opposed to clear or distinct.
Light and Materials
scatters
fuzzy detail
18.3 Behavior of Light
An opaque material either ___________ or ______________ all of the light that strikes it.
__________ materials are opaque.
An opaque object does ______
____________ any light to pass
through it.
Light and Materials
absorbs
reflects
Most
not
allow
18.3 Behavior of Light
Interactions of Light
When light strikes a _________ medium, the light can be…• __________________• __________________• __________________
If transmitted, or _________________, it can be refracted, polarized, or scattered.
new
reflected
absorbed
transmitted
passed through
18.3 Behavior of Light
Recall that when light encounters matter, some or all of the energy in the light can be ________________ to the matter.
Just as light can affect matter, _____________ can affect _____________.
Interactions of Light
transferred
matter
light
18.3 Behavior of Light
Reflection
An ____________ is a ____________ of an object formed by reflected (or refracted) waves of light.
Regular reflection occurs when parallel light waves strike a surface and reflect all in the __________ _____________________
Diffuse reflection occurs when parallel light waves strike a ____________, uneven surface and reflect in many ________________directions.
Interactions of Light
image copy
same direction
roughdifferent
18.3 Behavior of Light
Which example is regular reflection? And diffuse reflection?
Interactions of Light
regular diffuse
18.3 Behavior of Light
Refraction
A light wave can refract, or ____________, when it passes at an ______________ from one medium into another.
Refraction makes underwater objects appear _______________ and larger than they really are.
Refraction can also make an object appear to _____________ at the surface of the water.
Interactions of Light
bend
angle
closer
break
18.3 Behavior of Light
Because the light bends, the image you see appears to be bent as well.
Interactions of Light
18.3 Behavior of Light
Refraction can also sometimes cause a ______________, a false or distorted image.
• Mirages occur because light travels ______________ in ________ air than in cooler, denser air.
• Refraction causes some of the light to follow a __________________ path, rather than a straight path to the ground.
• Light that reaches your eyes after traveling in this manner can look as if it was reflected from a layer of ____________________.
Interactions of Light
mirage
fasterhot
curved
water
18.3 Behavior of Light
Light is refracted by hot air ___________ it reaches the ground
before
18.3 Behavior of Light
18.3 Behavior of Light
Polarization
Light with waves that vibrate in only ________ ___________ is polarized light.
Polarized light may occur when light reflects from a ________________ flat surface, such as a…
– __________________– surface of a _______________
Interactions of Light
one
plane
nonmetallic
window
lake
18.3 Behavior of Light
Polarization• Horizontally polarized light reflects more
____________ than the rest of the sunlight,
producing a _________________
• Polarized _________________ have vertically
polarized _______________ to block the
horizontally polarized light.
Interactions of Light
strongly
glare
sunglasses
filters
18.3 Behavior of Light
A vertical polarizing filter blocks light that is __________________ polarized.
Interactions of Light
Vertical polarizing filter
Horizontal polarizing filter
Vertical wave is blocked
Horizontal wave is blocked
Vertical wave passes through filter.
horizontally
18.3 Behavior of Light
Scattering
In scattering, light is ____________________ as it passes through a medium.
• Most of the particles in the atmosphere are very _____________.
• Small particles scatter ________
wavelength _________ light more
than light of longer wavelengths.
• Blue light is scattered in all
directions more than other colors
of light, which makes the _________ appear blue.
redirected
small
shorter
blue
sky
18.3 Behavior of Light
A scattering effect reddens the sun at ___________ and ______________
• When the sun is close to the horizon, sunlight travels ____________________ through the atmosphere.
• By the time the sunlight
reaches your eyes, most
______________-wavelength
light has been scattered.
• The remaining light consists
mostly of ____________ wavelength reds and oranges
Interactions of Light
sunset
sunrise
farther
shorter
longer
18.3 Behavior of Light
Assessment Questions
1. How do polarized sunglasses reduce glare? a. by scattering light as it passes through the glasses
b. by providing a smooth surface that light can reflect off
c. by absorbing all light
d. by blocking horizontally polarized light
18.3 Behavior of Light
Assessment Questions
2. An opaque material passes light through but scatters the light so that objects do not look clear.
TrueFalse
18.3 Behavior of Light
Assessment Questions
3. The following picture is an
example of… a. Reflection
b. Refraction
c. Polarization
d. Scattering
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