Waves, Sound, and Light
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.
1. Mechanical waves transfer energy
through a vacuum.
2. A wave is a disturbance that transfers
3. An example of a longitudinal wave is a
Light 3.1 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
• 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
• Technology is also a source of EM waves
Bell Work 11/30/10
1. What are the two types of
fields that make up an EM
2. How are EM waves used to
measure distances in space?
3. How does microwave cooking
depend on reflection?
• The range of all EM frequencies
• The spectrum goes from the lowest
frequencies to the highest
• Higher-frequency EM waves with
more electromagnetic vibrations per
second have more energy than lower-
frequency EM waves
Measuring EM Waves
• EM wave frequency is
measured in hertz (Hz)
• One hertz equals one cycle
• Have the longest wavelengths, the lowest
frequencies, and the lowest energies
• Examples of radio waves are AM/FM radio
and broadcast television
• EM waves with shorter wavelengths, higher
frequencies, and higher energy than other
• Radar – radio detection and ranging. Used to
control air traffic at airports, analyze weather
conditions and measure the speed of a
• Radar led to the invention of microwave
• Cell phones – radio transmitter and receiver
that uses microwaves
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
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.
Bell Work 12/1/09
1. What do electromagnetic waves
transfer energy through?
2. What is radiation?
3. How does a microwave cook
• The part of the EM spectrum that human
eyes can see.
• Longest wavelengths are red all the way to
• ROY G BIV
• Red, Orange, Yellow, Green, Blue, Indigo,
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.
• Type of EM wave most often associated
• Sometimes referred to as heat rays
• You can feel it as warmth coming from the
sun, a fire, or a radiator
• Infrared lamps are used to provide warmth
in bathrooms and to keep food warm after
its been cooked
• Some animals can see in infrared light
• Has more energy than visible light
• The waves in this range can damage your skin and
• Sun block and UV-protection sunglasses are
designed to filter out the higher frequencies
• UV light can be used to sterilize medical instruments
and food by killing harmful bacteria
• IV light causes skin cells to produce vitamin D which
is essential to good health
• UV light is visible to some animals. Bees and some
• Has a very high frequency and energy
• Pass easily through soft tissues of the
body, but are absorbed by the bone
• The x-rays pass through exposing the film
where there is no bone
• When getting x-rays other parts of the
body are covered with a lead vest to block
• Highest frequencies and energies of any
• Produced by some radioactive substances
as well as the sun and other stars
• 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
cancer cells and fight 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
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)
Incandescence – the production of
light by materials at high
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
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
3. What produces the most EM waves on
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
How Materials Transmit Light
• Transparent materials allow most of
the light that strikes them to pass
• 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
• Scattering creates a glare and makes it
hard to see even through a transparent
Polarization – a quality of light in which
all of its waves vibrate in the same
• 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
• 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
• 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
Bell Work 12/8/09
1. What color is something that absorbs all
2. What color is something that reflects all
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
2. When light is absorbed into a medium, the
waves ________ in the medium.
3. The primary pigments create colors through
4. An electromagnetic wave transfers energy
through a ______.
5. Most of the visible EM waves on Earth
come from the ______.