Transcript Reflection and Refraction

Topic: Waves
Aim: Describe the properties and behavior of
visible light.
Do Now: Take out reproduction packet.
Complete #2 on the back of your KE and PE
reading notes.
HW: Reading Notes – Forces
CL Waves due Thursday
Which skier will have a greater potential
energy? Support your answer.
Identify the electromagnetic wave
described.
1. Has the highest energy.
2. Used to look at internal images of bones.
3. Needed for your cells to produce Vitamin D.
4. Lowest frequency and wavelength.
5. Visible light with the shortest wavelength.
6. Felt as heat.
7. Emitted by cell phones and satellite signals.
8. Produced during nuclear reactions.
Light
• Electromagnetic wave
• Transverse wave
Photon
• Tiny bundle of energy
• Continue in straight line
unless direction is changed
What
occurs
when
light
strikes
an
object?
Which is transparent,
translucent, and opaque?
Opaque • Doesn’t transmit light
•
Only
absorbs
&
object
reflects
• Wood, metal…
Translucent• Transmits light,
but with no detail
object
• Some light passes
• Waxed paper, frosted glass
Transparent • Transmits light easily
object
• Very clear
• Water, glass, air…
You can’t see the stem of this flower through the
opaque vase. A blurry view of the stem is seen
through the translucent vase. The entire stem can
clearly be seen through the transparent vase.
Reflection • Bouncing back of light
• Law of Reflection = angle of
incidence = angle of reflection
Types of • Depends
reflection
on surface
Regular Reflection
SHARP IMAGE
Diffuse Reflection
FUZZY IMAGE
Regular Reflection
Diffuse Reflection
Refraction • Bending of light
• Ray changes speed
Index of
Refraction
• Amount by which a
material refracts light
• Greater = more light is
bent
• Larger for solids
• Smallest for gases
B has a larger
Index of Refraction
because it bends
the wave a lot more
than A
C has a larger
Index of Refraction
because it bends
the wave a lot more
than D
Prism
• Piece of glass
• Bends white light
2x
• Separates it into
colors (different
wavelengths)
• Longer wavelength  less
bending
Red • Longest wavelength
light • Refracted the least
Violet• Shortest wavelength
•
Refracted
the
most
light
When water droplets act as a
prism, a RAINBOW is formed.
Diffraction: light bends when it passes
around an edge or through a slit
Mirages result when air near the ground is much
warmer or cooler than air above. The density of air
increases as air cools and light waves move slower in
cooler air than warmer air. As a result, light waves
are refracted as they pass through air layers with
different temperatures.
Let’s summarize…
1. Compare the angle of incidence and the
angle of reflection.
2. Describe the difference between reflection
and refraction.
A student sees a mirror image of a
duck in the water of a lake. What
causes the mirror image?
a. Black light
b. Refracted light
c. Reflected light
d. Absorbed light
What happens to the path of a light ray as it
passes from air into water at an angle?
a. Its path widens.
b. Its path bends.
c. Its path becomes shorter.
d. Its path continues in a straight line.
Objects appear different in size and shape in a
container of water due to
a. refraction of light waves
b. interference of the water and light waves
c. polarization of the light waves
d. diffraction of the light waves