Ch 20 The Energy of
Waves
Material on Final Exam
Section 1: The Nature of Waves
wave
• A _________
is any disturbance that transmits
energy through matter or space
• Some waves use a medium to travel through
medium
• A _______________
is a substance through which a
wave can travel
liquid or ________
solid __________,
gas
• Can be a __________,
mechanical
• These waves are called ____________________
waves
• If a wave does not travel through a medium, it is
electromagnetic
called an ____________________________
wave, or EM wave for short
Section 1: The Nature of Waves
• There are three major types of waves
Transverse
• 1. ____________________
waves
• Transverse waves have the particles move in an up-anddown motion.
perpendicular
• Aka _________________________
• ____________
Crests are the top of the wave
• ____________
Troughs are the bottom of the wave
Section 1: The Nature of Waves
• Label the diagram below:
• Crest, trough, vibration direction, wave direction
Wave direction
Crest
Vibration
Direction
Trough
Section 1: The Nature of Waves
Longitudinal
• _______________________
waves
• Longitudinal waves have the particles move in a side-to-side
motion
• Aka ___________________
Parallel
Compression
• The crowded space is called a ___________________
• The spread out space is called a __________________
Rarefaction
Section 1: The Nature of Waves
• Label the diagram below
• Compression, Rarefaction, vibration direction, wave
direction
Wave direction
Compression
Vibration Direction
Rarefaction
Section 1: The Nature of Waves
Surface
• ________________
waves
• Surface waves are combinations of __________________
transverse
longitudinal waves
waves and ___________________
circles
• The particles move in ______________
Section 1: The Nature of Waves
• Section 1 Practice
• WORD BANK: ELECTROMAGNETIC, ENERGY, MEDIUM,
LONGITUDINAL, TRANSVERSE
• In a ______________
longitudinal wave, the particles vibrate parallel
to the direction that the wave travels.
medium through
• Mechanical waves require a ____________
which to travel
transverse
• In a ________________
wave, the particles vibrate
perpendicular to the direction that the wave travels.
• All waves transfer __________________.
energy
electromagnetic
• An _________________________________
wave does
not require a medium.
Section 2: The Properties of Waves
amplitude
• The ____________________
of a wave is its height
• The ____________
the amplitude, the __________
bigger
higher the
energy of a wave
lower
• The ____________
the
smaller the amplitude, the ___________
energy of a wave
Section 2: The Properties of Waves
• Circle the wave with more energy
Section 2: The Properties of Waves
wavelength
• The ____________________
is the distance between
two crests or two compressions next to each other in
a wave.
shorter
higher
• The _______________
the wavelength, the ____________
the energy
longer
lower
• The _______________
the wavelength, the ____________
the energy
Section 2: The Properties of Waves
• Circle the wave with more energy
Section 2: The Properties of Waves
frequency
• The __________________
of the wave is the
number of waves produced in a given time
Hertz
• Units are ____________
(1 Hz = 1/s)
Section 2: The Properties of Waves
inverse
• Wavelength and frequency have an _____________
relationship
• A longer wavelength has a ___________
lower frequency
• A shorter wavelength has a ___________
higher frequency
• The _______________
the frequency, the
higher
higher
___________
the energy
• The _______________
the frequency, the
lower
lower
___________
the energy
Section 2: The Properties of Waves
• Circle the wave with more energy
Section 2: The Properties of Waves
• Section 2 Practice
• Label the wavelength, crest, trough, amplitude for
the wave below
amplitude
wavelength
trough
crest
Section 3: Wave Interactions
Reflection
• ___________________
happens when a wave
bounces back after hitting a barrier
• Water, sound, light
• Reflection of sound is called an _______________.
echo
Refraction
• ____________________
is the bending of a
wave as the wave passes from one medium to
another at an angle
• When a wave moves from one medium to another,
the wave’s ___________
changes.
speed
Section 3: Wave Interactions
Section 3: Wave Interactions
Dispersion
• _________________
is when light is spread out
into different colors
prisms
• This happens with _____________
• White light is made of many colors that spread out
Diffraction
• ___________________
is when waves bend
around a barrier
Sound
• ______________
waves are bigger, so they bend
around a corner more easily
Light
• ______________
waves are smaller, so they do not
bend as easily
Section 3: Wave Interactions
Section 3: Wave Interactions
Interference
• _____________________
is when two or more
waves overlap one another
Constructive
• _______________________
interference is when two
waves overlap to produce a larger wave
Destructive
• _______________________
interference is when two
waves overlap to produce a smaller wave
• A ________________
wave is when certain parts
standing
of the wave are always at the rest position
• Examples: jump rope, music notes
Section 3: Wave Interactions
Section 3: Wave Interactions
• Section 3 review
Diffraction
_________________________
is the bending of a wave around
a barrier
Constructive
_________________________
_________________________
is when
Interference
two waves overlap to produce a larger
wave
Section 3: Wave Interactions
• Section 3 review
_________________________
is
Dispersion
when white light separates into all
the different colors
_________________________
is when
Reflection
a wave bounces off a barrier
Section 3: Wave Interactions
• Section 3 review
An ____________
echo is the
reflection of a sound wave
Refraction is
_____________________
the bending of a wave as it
moves from one medium to
another
Section 3: Wave Interactions
• Section 3 review
Destructive
_________________________
_________________________
interference
is when two waves overlap to
produce a smaller wave
standing wave
A __________________________
always has parts at rest