TOPIC: Waves AIM: What are the properties of waves?

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Topic: Waves
Aim: Describe the parts of a wave.
Do Now: Take out your HW ditto
http://www.youtube.com/watch?v=Z3O2Ju3ULvo
HW: Bottom of Kinetic and Potential Energy ditto/
Identify the type of wave described below.
1. Does not require a medium.
2. Compressional waves
3. Particles of the medium move PARALLEL to
the direction of the wave.
4. Requires a medium.
5. Can travel through a vacuum.
6. Particles of the medium move at RIGHT
ANGLES to the direction of the wave.
7. Sound waves
Parts of a
Transverse wave
y- axis
x- axis
Normal resting
position
Crest
Trough
•Crest – high points
•Trough – lowest
points
Crest
Trough
Amplitude
•Amplitude – height
–Related to energy
–High amp = a lot of
energy
•Wavelength – distance
bw 2 crests or 2
troughs
Wavelength
Wavelength
• compression =
Parts of a
Compressional where particles
are
close
together
(longitudinal)
• rarefaction =
wave
where particles
are far apart
rarefaction
compression
• Wavelength = Distance bw 2
compressions or 2
rarefactions
wavelength
• High amplitude:
– compression = particles are very
close together
– rarefaction = particles are very
far apart
•
#
of
waves
passing
a
Frequency
point in a given time
• 1 wave = 1 crest + 1
trough
• As frequency increases,
wavelength decreases
1 second
Hertz
•Unit for
frequency
•Hz
•1 Hz = 1 wave
per second
The human ear is capable of detecting sound
waves with a wide range of frequencies,
ranging between approximately 20 Hz to
20,000 Hz.
Period
• Time it takes 1
wavelength to
pass a point
• Units = seconds
• As frequency
increases, period
decreases
Low
period
High
period
Let’s summarize…
1. Describe the parts of a transverse wave.
2. Describe the parts of a longitudinal wave.
3. Describe the frequency of a wave.
4. Describe the relationship between frequency
and wavelength.
5. Identify the units for frequency.
6. Describe the period of a wave.
7. Describe the relationship between frequency
and period.
http://www.brainpop.com/science/energy/waves/
A
B
C
D
Identify each part of a wave labeled in the
diagram above.
Which change in wave properties
increases wave amplitude?
1. Increased wavelength
2. Increased height
3. Decreased frequency
4. Shortened wavelength
Which is the lowest part of a
transverse wave?
1.Amplitude
2.Crest
3.Period
4.Trough
The height of a transverse wave is
known as its
1.amplitude
2.crest
3.period
4.trough
The part of a longitudinal waves
where particles are farther apart is
known as the
1.crest
2.compression
3.trough
4.rarefaction
Which of the following changes in wave
properties is a result of an increase in
wavelength?
1. Higher crests
2. Reduced height
3. Lower frequency
4. Faster movement
The number of waves passing a
point at a given time is known as
1. wavelength
2. frequency
3. period
4. amplitide
The time it takes one wavelength
to pass a certain point is known as
1. wavelength
2. frequency
3. period
4. amplitude
Which of the following best describes the
relationship between frequency and wavelength?
1. If the frequency remains constant, wavelength
increases.
2. The wavelength decreases and frequency
decreases.
3. The frequency increases as wavelength
decreases.
4. If the wavelength remains constant, frequency
increases.
1. Which wave has the greatest amplitude?
2. Which wave has the greater wavelength?
3. Which wave has the greater frequency?
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