Waves, Sound, and Light
Chapter 3
Bell Work 11/29/10
Please get a new bell work sheet. Write
each statement then decide if they are
true or false, if false correct them.
• Mechanical waves transfer energy
through a vacuum.
• A wave is a disturbance that transfers
energy.
• An example if a longitudinal wave is a
water wave.
Bell Work 11/24/09
Please begin working
on your
electromagnetic
poster.
Bell work 11/25/09
1. List the colors of the visible light
spectrum in order from longest
wavelength to shortest wavelength.
2. What are the 7 parts of the
electromagnetic spectrum?
Bell Work 12/2/09
1. What are EM waves measured in?
2. Give two examples of using a radio wave.
3. Give 3 examples of using a microwave.
4. List the colors of visible light from longest
wavelength to shortest wavelength.
Bell Work 11/30/09
Please use complete sentences
1. Give an example of using a radio wave.
2. Give an example of using a microwave.
3. Give an example of using an x-ray.
1.1 Vocab
Electromagnetic wave – a disturbance that
transfers energy through a field
Radiation – energy that moves in the form
of EM waves
How EM waves form and sources
of EM waves
• Electric and magnetic fields make up EM
waves
• Many of the EM waves on Earth’s
environment come from the Sun.
• Stars give off EM waves but since they are
so far away not many of their waves hit the
Earth
• Technology is also a source of EM waves
Bell Work 11/30/10
1. What do electromagnetic waves
transfer energy through?
2. What is radiation?
3. How does a microwave cook
food?
Electromagnetic spectrum
• The range of all EM frequencies
• The spectrum goes from the ______
frequencies to the
_______frequencies
• ______-frequency EM waves with
more electromagnetic vibrations per
second have more energy than
_____-frequency EM waves
Measuring EM Waves
• EM wave frequency is
measured in _____ (Hz)
• One hertz equals one cycle
per ______
Welcome to December
Bell Work 12/1/10
1. What is the electromagnetic spectrum?
State whether each statement is true or false. If
false make the statement true.
2. Mechanical waves transfer energy through a
vacuum.
3. A wave is a disturbance that transfers energy.
4. Most EM waves are invisible but detectable.
Radio waves
• Have the ______ wavelengths, the
______ frequencies, and the ______
energies
• Examples of radio waves are AM/FM radio
and broadcast television
Microwaves
• EM waves with ______ wavelengths, higher
frequencies, and _____ energy than other
radio waves
• Radar – radio detection and ranging. Used to
control air traffic at airports, analyze
________ conditions and measure the speed
of a moving vehicle
• Radar led to the invention of ________
ovens
• Cell phones – radio transmitter and receiver
that uses ________
Infrared Light
• Type of EM wave most often associated
with ______
• Sometimes referred to as _____ rays
• You can feel it as warmth coming from the
sun, a fire, or a radiator
• Infrared lamps are used to provide ______
in bathrooms and to keep food warm after
its been cooked
• Some animals can see in _____ light
Visible Light
• The part of the EM spectrum that _____
eyes can see.
• Longest wavelengths are _____ all the
way to violet
• ROY G BIV
• Red, Orange, Yellow, Green, Blue, Indigo,
Violet
Ultraviolet Light
• Has more energy than _____ light
• The waves in this range can ______ your skin and
eyes
• Sun block and UV-protection sunglasses are
designed to filter out the _______ frequencies
• UV light can be used to sterilize medical instruments
and food by _____ harmful bacteria
• UV light causes skin cells to _______ vitamin D
which is essential to good health
• UV light is ______ to some animals. Bees and some
other insects
X-rays
• Has a very ______ frequency and ______
• Pass easily through soft tissues of the
body, but are absorbed by the _____
• The _______ pass through exposing the
film where there is no bone
• When getting x-rays other parts of the
body are covered with a _____ vest to
block the x-rays
Gamma rays
• ________ frequencies and energies of any
___ waves
• Produced by some radioactive substances
as well as the ____ and other _____
• Gamma rays can penetrate the soft and the
hard tissues of the body, killing normal cells
and causing cancer cells to develop
• Gamma rays can also be used to kill _____
cells and _____ tumors
Bell Work 12/3/09
1. Which group from the EM spectrum has
the highest frequencies?
2. Which group pass easily through soft
tissues of the body, but are absorbed by
the bone?
3. What can you use to filter out the high
frequencies of UV rays?
4. Which EM wave is most associated with
heat?
Bell Work 12/4/09
Predict what would happen if
you kept a green plant in the
dark for one month. Explain
why. (at least 3 sentences)
Vocab 3.3
Incandescence – the production of
light by materials at high
temperatures
Luminescence – the production of
light without the high temperature.
Many organisms produce their own
visible light through this.
Bioluminescence – production of
light by living organism. These
organism produce light from
chemical reactions rather than
intense heat.
Fluorescence – occurs when a
material absorbs EM radiation of
one wavelength and gives off EM
radiation of another.
Bell Work 12/5/09
1. What happens to the speed of EM waves
in a vacuum?
2. What happens when microwaves
encounter water?
3. What produces the most EM waves on
Earth?
Light 3.4 Notes
Transmission – the passage of an
EM wave through a medium.
• If the light reflected from objects
did not pass through the air,
windows, or most of the eye, we
could not see the objects
Absorption – the
disappearance of an EM
wave into the medium
• Absorption affects how things
look, because it limits the light
available to be reflected or
transmitted
How Materials Transmit Light
• Transparent materials allow most of
the light that strikes them to pass
through.
• Translucent materials transmit some
light, but they also cause it to spread
out in all directions.
• Opaque materials do not allow any
light to pass through them, because
they reflect light, absorb light, or both
Scattering – the spreading out of light rays
in all directions, because particles reflect
and absorb the light
• Fog or dust in the air, mud in water, and
scratches or smudges on glass can all
cause scattering
• Scattering creates a glare and makes it
hard to see even through a transparent
material
Polarization – a quality of light in which
all of its waves vibrate in the same
direction
• Polarizing filters reduce glare and make
it easier to see objects
Prism – a tool that uses refraction to
spread out the different wavelengths
that make up white light
• Prisms split light into colors by refracting
wavelengths in different amounts
Color Reflection and Absorption
The color of an object or material is
determined by two factors
1. the wavelengths it absorbs and
those it reflects
2. The wavelengths present in the light
that shines on the object
• A material that reflects all wavelengths
of visible light appears white
• A material that absorbs all
wavelengths of visible like appears
black
• A green lime absorbs most
wavelengths but reflects green, so the
lime looks green
Primary Colors of Light
• The human eye can detect only 3
color bands: red, green, and blue
• Your brain perceives these three
colors and various mixtures of them
as all the colors
Primary colors – red, green, and blue
– can be mixed to produce all the
possible colors
Primary Pigments
• Materials can be mixed to produce
colors just as light can
• Materials that are used to produce
colors are called pigments
Primary pigments – cyan, yellow, and
magenta
Bell Work 12/8/09
1. What color is something that absorbs all
the colors?
2. What color is something that reflects all
colors?
3. If an object absorbs most wavelengths
but reflects violet what color will it be?
Bell Work 12/9/09 – (fill in the blanks)
1. Bioluminescent animals produce light
through _________.
2. When light is absorbed into a medium, the
waves ________ in the medium.
3. The primary pigments create colors through
_____________ mixing.
4. An electromagnetic wave transfers energy
through a ______.
5. Most of the visible EM waves on Earth
come from the ______.