Focus: Waves
Objective: Explain what transverse and
longitudinal waves are, how they are
alike and how they are different. We will
be able to say how they occur in
earthquakes.
Vocabulary to Know
What is a
wave?
Examples:
In the Ocean
A wave is a type of
energy.
Waves transfer
energy not matter.
In the Clouds
Earthquake
Sound waves are longitudinal.
Longitudinal waves
Transverse waves
Seismic waves are what we call the waves that
happen during an earthquake.
• When an earthquake happens, energy waves vibrates
through the earth’s crust as the crust bends or breaks.
During an earthquake, there are both:
• Transverse waves
• Longitudinal waves
Which wave travels faster?
Think-Pair-Share:
• Think about the slinky
• Let’s find out!
– Human wave activity
Since the energy is traveling the fastest way it can (in a straight line), the
longitudinal wave is faster than the transverse wave. It gets from the
force to the stopping point first. It is the first wave you feel in an
earthquake.
The transverse wave takes more time and energy to go perpendicular to
the direction of the wave. You feel this wave second in an earthquake. It
is sometimes called the “aftershock”.
Which wave does more damage?
Think-Pair-Share:
Write the questions and answer them
in your interactive notebook.
1. Which wave do you
think would do more
damage to a city? Write
this as a hypothesis. (“I
think…because…”
2. Why do you think so?
• Let’s find out!
– Human wave activity with
buildings
What are the parts of a wave?
Transverse wave
**WRITE THIS DOWN**
The crest is the highest point on a transverse
wave. The trough is the lowest point on a
transverse wave.
The rest position of the wave is called the node or nodal
line.
**WRITE THIS DOWN**
What do we call The top of the wave is the CREST.
the tops and
The bottom of the wave is the
bottoms of
TROUGH.
waves?
What are the parts of a wave?
Transverse wave
**WRITE THIS DOWN**
The wavelength is the distance from one
point on the wave to the same point on the
next wave.
SLINKY LAB
Compressional
Longitudinal wave
On a compressional wave
the (**WRITE THIS
DOWN**) area squeezed
together is called the
compression. The areas
spread out are called the
rarefaction.
(**WRITE THIS DOWN**)The
wavelength is the distance
from the center of one
compression to the center
of the next compression.
SLINKY LAB
**WRITE THIS DOWN**
The amplitude of a transverse wave is determined by
the height of the crest or depth of the trough
**WRITE THIS DOWN**
What is
amplitude?
Amplitude is the height of the
wave. It is how high and how
low the waves go.
What is wavelength? (**WRITE IT DOWN**)
Wavelength is a measure of distance, so the units for
wavelength are always distance units, such as meter,
centimeters, millimeters, etc.
What is wave frequency?
Frequency is the number of waves that pass through
a point in one second. The unit for frequency is waves
per second or Hertz (Hz). One Hz = One wave per
second. (**WRITE THAT DOWN**)
The smaller the wavelength, the more times it will pass through a
point in one second. The larger the wavelength, the fewer times it
will pass through a point in one second.
Focus: Waves
Objective: Compare the properties of waves to
the wavelike property of energy in earthquakes,
light and sound.
EQ: What are the 2 kinds of mechanical
waves? How are they similar? How are
they different?
WAVES
Vocabulary to Know
What is a
wave?
Examples:
In the Ocean
A wave is a type of
energy.
Waves transfer
energy not matter.
In the Clouds
Earthquake
Sound waves are longitudinal.
Longitudinal waves
Transverse waves
Seismic waves are what we call the waves that
happen during an earthquake.
• When an earthquake happens, energy waves vibrates
through the earth’s crust as the crust bends or breaks.
During an earthquake, there are both:
• Transverse waves
• Longitudinal waves
Which wave travels faster?
Think-Pair-Share:
• Think about the slinky
• Let’s find out!
– Human wave activity
Since the energy is traveling the fastest way it can (in a straight line), the
longitudinal wave is faster than the transverse wave. It gets from the
force to the stopping point first. It is the first wave you feel in an
earthquake.
The transverse wave takes more time and energy to go perpendicular to
the direction of the wave. You feel this wave second in an earthquake. It
is sometimes called the “aftershock”.
Which wave does more damage?
Think-Pair-Share:
Write the questions and answer
them in your interactive notebook.
1. Which wave do you
think would do more
damage to a city?
2. Why do you think so?
• Let’s find out!
– Human wave activity
with buildings
What are the parts of a wave?
Transverse wave
The crest is the highest point on a transverse
wave. The trough is the lowest point on a
transverse wave.
The rest position of the wave is called the node
or nodal line.
Vocabulary to Know
What do we call The top of the wave is the CREST.
the tops and
The bottom of the wave is the
bottoms of
TROUGH.
waves?
What are the parts of a wave?
Transverse wave
The wavelength is the distance from one
point on the wave to the same point on the
next wave.
Compressional
Longitudinal wave
On a compressional wave
the area squeezed
together is called the
compression. The areas
spread out are called the
rarefaction.
The wavelength is the
distance from the center of
one compression to the
center of the next
compression.
The amplitude of a transverse wave is determined by
the height of the crest or depth of the trough
Vocabulary to Know
What is
amplitude?
Amplitude is the height of the
wave. It is how high and how
low the waves go.
What is wavelength?
Wavelength is a measure of distance, so the units for
wavelength are always distance units, such as meter,
centimeters, millimeters, etc.
What is wave frequency?
Frequency is the number of waves that pass through a
point in one second. The unit for frequency is waves per
second or Hertz (Hz). One Hz = One wave per second.
Wavelength and frequency are inversely related.
The smaller the wavelength, the more times it will pass through a
point in one second. The larger the wavelength, the fewer times it
will pass through a point in one second.
Vocabulary to Know
What is
frequency?
Frequency is the number of
crests OR troughs in a given
space or time.
3
3
How many crests?
How many troughs?
http://id.mind.net/~zona/mstm/physics/waves/introduction/introductionWaves.html
Waves have measurable
properties
Frequency is the number of waves (vibrations)
that pass through a point in one second.
Period is the time it takes for one full
wavelength to pass a certain point.
Frequency is waves per second.
Period is seconds per wave.
1
frequency 
period
1
f
T
A wave moving through a medium travels at a certain
speed. This is Wave Speed.
Wave speed is usually measured in meters/second, but
may be measured using other distance units (such as
centimeters per second).
How is Wave Speed calculated?
Wave speed is calculated as the product of a waves
frequency and wavelength.
Wavelength is represented by the Greek letter lambda
(λ) and frequency is represented by (f)
Vocabulary to Know
What is
frequency?
Frequency is the number of
crests OR troughs in a given
space or time.
3
3
How many crests?
How many troughs?
http://id.mind.net/~zona/mstm/physics/waves/introduction/introductionWaves.html
Waves have measurable
properties
Frequency is the number of waves (vibrations)
that pass through a point in one second.
Period is the time it takes for one full
wavelength to pass a certain point.
Frequency is waves per second.
Period is seconds per wave.
1
frequency 
period
1
f
T
A wave moving through a medium travels at a certain
speed. This is Wave Speed.
Wave speed is usually measured in meters/second, but
may be measured using other distance units (such as
centimeters per second).
How is Wave Speed calculated?
Wave speed is calculated as the product of a waves
frequency and wavelength.
Wavelength is represented by the Greek letter lambda
(λ) and frequency is represented by (f)