Waves Unit Test Review
Waves, Sound, Light, and Color
Winter 2014
Define a wave.
• Caused by disturbance
• Carries energy (and SOMETIMES particles)
List 4 ways we categorize waves.
• Mechanical: require a medium (matter) to travel;
ALL longitudinal waves are mechanical; SOME
transverse waves are mechanical.
• Transverse: move particles perpendicular to
direction; not all require a medium; can carry
energy AND particles.
• Longitudinal: particles vibrate back and forth to
direction; all require a medium
• Electromagnetic: ALL transverse waves; ONLY
carry energy (NOT particles)
What do ALL waves carry?
What can waves carry in a medium?
• All waves carry ENERGY!
• Waves traveling in a medium can carry energy
AND particles!
Differentiate between the 2 types of
interference.
• Constructive Interference: waves combine to
form larger waves
• Destructive Interference: waves combine to
cancel each other out
Draw and Label ALL the parts of a
transverse wave.
State 3 characteristics of a transverse
wave.
• Moves particles perpendicular to direction of
the wave
• Many do NOT require a medium
• ALL electromagnetic waves are transverse
What is frequency?
How is it measured?
•
•
•
•
Frequency is the number of waves per second
Measured in Hertz (Hz)
High frequency = high energy
Low frequency = low energy
What is amplitude?
How does intensity relate to amplutude?
• Amplitude is the distance the wave moves
from the rest position (equilibrium)
• Frequently referred to as “wave height”
• More amplitude = more energy (intensity)
• Intensity = energy!
Draw and Label ALL the parts of a
longitudinal wave.
State 3 characteristics of a longitudinal
wave.
• Particles vibrate back and forth parallel to
direction of wave
• ALL require a medium!
• ALL sound waves are longitudinal!
How does the speed of sound vary in
traveling through solids, liquids, and gases?
• Speed travels BEST (fastest) through solids
(the particles are already touching!)
• Speed travels GOOD (medium) through liquids
(particles are still touching, but spread apart
to slip by each other)
• Speed travels OK (slowest) through gases
(particles are spread out)
How does temperature play a part in
how longitudinal waves travel?
• Sound travels FASTER in WARMER
temperatures.
• Sound travels SLOWER in COLDER
temperatures.
Draw and example of reflection,
refraction, diffraction, and absorption.
Reflection
Diffraction
Refraction
Absorption
How does sound travel?
• In a longitudinal waves that require a
medium!
What do frequency and pitch have in
common?
• Frequency determines pitch.
What does high and low frequency
indicate in relation to pitch?
• High frequency = high pitch (high
energy/intensity) and short wavelength
• Low frequency = low pitch (low
energy/intensity)and longer wavelength
How are amplitude and loudness
related?
• Amplitude determines loudness.
• High amplitude = increases loudness
• Low amplitude = decreased loudness
What is the Doppler Effect? Give an
example.
• Doppler Effect is the apparent change in
frequency as a sound source moves toward a
listener. Also called Red shift/Blue Shift!
Red Shift/Blue Shift
• Example: emergency sirens
Doppler Effect
What is loudness? What unit do we
use to measure loudness?
• Loudness is the amplitude (height) of a sound
wave.
• Loudness is measured in decibels (db)
What is an echo?
• An echo is a reflected sound wave.
What is resonance?
• Resonance occurs when objects near one
another vibrate at the same frequency.
Click on the link to watch
resonance in action!
http://www.youtube.com/watch?v=17tqXgvCN
0E
At what average speed can sound
travel through air?
• Sound travels @ 330 m/s through air.
Does sound travel faster through
warmer or cooler temperatures?
• Sound travels faster through warmer air.
• Sound refracts DOWN in warmer air
• Sound refracts UP in cooler air
Explain how the electromagnetic spectrum is organized. Which
waves have the longest wavelength? Which waves have the
shortest wavelength?
• The EM Spectrum consists of ALL
electromagnetic waves organized by
WAVELENGTH and FREQUENCY.
• From LONGEST to SHORTEST (lowest energy to
highest energy): radio, microwave, infrared,
visible light (ROY G BIV), ultraviolet (UV), x-ray,
and gamma
• Longest wavelength = RADIO
• Shortest wavelength = GAMMA
EM Spectrum!
How does frequency play a role in the
organization of the EM spectrum?
• Higher the frequency, higher the energy,
shorter wavelength
• Lower the frequency, lower the energy, longer
wavelength
What do electromagnetic waves carry?
•ENERGY ONLY!!!
What categories of waves describe
light?
• Transverse and Electromagnetic – NO
MEDIUM REQUIRED!!
What is the Law of Reflection? Draw
an example.
• Law of Reflection states that light reflects off
at the same angle that it strikes an object.
How fast can light travel?
• The speed of light is @ 300,000,000 m/s.
• Takes @ 8 minutes for light from the sun to
reach the Earth.
Why can we see objects?
• We see objects because they either produce
their own light OR they reflect light!
What are the 3 primary colors of light? When
combined in equal parts, what do they create?
• 3 primary colors of light: RED, BLUE, GREEN
• When mixed in EQUAL portions, they create
WHITE light!
What are the 3 primary colors of pigments? When
combined in equal parts, what do they create?
• 3 primary PIGMENT colors are: CYAN,
MAGENTA, and YELLOW!
• When mixed in EQUAL parts, they create
BLACK!
Why can we see the color white?
• ALL colors are reflected!
Why can we see the color black?
• ALL colors are absorbed!
Why is an apple red or a banana yellow? What
happens when we shine a different color light on these
objects?
• The color of ANY object is the color that it
REFLECTS! ALL other colors are absorbed!
In regard to the visible light spectrum. Which color has the
longest wavelength and lowest frequency? Which color has the
shortest wavelength and highest frequency?
RED has the
longest
wavelength and
lowest
frequency.
Violet/Purple
has the shortest
wavelength and
the highest
frequency.
Complete the table.
Energy
Reflection
Refraction
Diffraction
Absorption
Scattering
Sound
An echo is a
reflected
sound wave.
Sound can
refract as it
changes
speeds in
media.
Sound
Sound can
diffracts well be
around a
absorbed.
barrier.
Sound can
be scattered
by changing
media.
Light can be
reflected.
Light can be
refracted.
Light can be
diffracted.
Light
scatters very
easily.
Draw an
example
Light
Draw an
example
Light can be
absorbed.
Complete the Table
Type of Object
Reflection
Transmission
Scattering
Absorption
Transparent
Minor energy
reflection
Most energy
transmits
No scattering
No absorption
Minor energy
reflection
Minor energy
transmission
Most energy
scatters
Minor
absorption
Light reflected
is what we see
No
transmission
No scattering
Most energy is
absorbed
Draw an
example
Translucent
Draw an
example
Opaque
Draw an
example
What is a plane mirror? What kind of
reflection does it produce?
• A plane mirror is a flat mirror that produces
regular reflection.
Draw and Label an example of a
concave and convex mirror.
Convex Mirror
What do concave and convex mirrors do?
Concave mirrors
produce an image
that is upside
down…like looking
at the INSIDE of a
spoon.
Convex mirrors
produce an
image that is
right side up, yet
a little
elongated…like
the BACK of a
spoon.
Draw and label an example of a
concave and convex lens.
What type of lenses would be used to correct
nearsightedness? What type of lenses would be used to
correct farsightedness?
Nearsightedness = myopia
• Eyeball is too long.
• Can see near. Distance
vision is not great.
• Can be corrected with a
combination of convex and
concave lenses (glasses or
contacts.)
• Additionally, Lasic eye
surgery is an option. This
procedure uses lasers to
reshape the eye to correct
blurry distance vision.
Farsightedness – hyperopia
• Eyeball is too short.
• Can see far. Close up vision
is not great.
• Can only be corrected with
convex lenses (glasses or
contacts.)
• Convex lenses clarify a
blurry image.