March 16, 2015
• Answer Brain Pop Quiz questions as an
anticipation guide (correct while viewing)
• On the back, make a double bubble map
comparing and contrasting transverse and
longitudinal waves
• Homework: Read and take notes on chapter
20, section 3. Skills tutor due Friday.
March 17, 2015
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Complete Parts of a Wave WS front & back
Take out Anatomy of a Wave WS
Take out 20.3 notes
Number a piece of paper 1 – 8 (skip spaces)
Homework: Read and take notes on chapter
21, sections 1 & 2.
Investigations
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Rotate among the 8 activities
Read the directions and complete the activity
Record your observations
Answer questions in italics
March 18, 2015
• Write a scientific argument based on
yesterday’s activities
• Take out your notes
• Homework: Read and take notes: chapter 21,
section 3 & 4. SkillsTutor due Friday
March 20, 2015
• Read “Glassical Music” on page 6 of Current
Science – pay attention to the vocabulary
• Take out notes on chapter 21, sections 3 & 4
• No homework!
Glassical Music Answers
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1. friction
2. brain
3. high
4. distilled
5. wavelength
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6. compression
7. brain
8. vibrate
9. rarefaction
10. pitch
Waves, Sounds, and Light
Standards
• SPS9. Students will investigate the properties of waves.
• a. Recognize that all waves transfer energy.
• b. Relate frequency and wavelength to the energy of
different types of electromagnetic waves and mechanical
waves.
• c. Compare and contrast the characteristics of
electromagnetic and mechanical (sound) waves.
• d. Investigate the phenomena of reflection, refraction,
interference, and diffraction.
• e. Relate the speed of sound to different mediums.
• f. Explain the Doppler Effect in terms of everyday
interactions.
A wave is a disturbance that
transmits energy.
The particles of a medium do not
travel with the wave.
Mechanical waves require a medium,
but electromagnetic waves do not
Particles in a longitudinal wave vibrate
parallel to the direction that the wave
travels.
Particles in a transverse wave vibrate
perpendicularly to the direction the
wave travels.
Link
Wave Properties
• Amplitude is the maximum distance the
particles of a medium vibrate from their rest
position.
• Wavelength is the distance between two
adjacent corresponding parts of a wave.
• Frequency is the number of waves that pass a
given point in a given amount of time.
• Wave speed can be calculated by multiplying
the wave’s wavelength by the frequency.
Wavelength
The shorter the
wave, the
higher the
energy!
Frequency
The higher the
frequency, the
higher the energy!
Wave Modeling Spring
• How do transverse & compression waves
compare?
• How do they contrast?
• What effect does increasing the energy into
the wave have?
• What relationship do you see between wave
frequency and wavelength?
• Waves on a String PhET
Anatomy of a Wave
• Part 1 – Label the wave according to directions
• Part 2 – create waves on the back as follows:
Wave Interactions
• Waves reflect after hitting a barrier.
• Refraction is the bending of a wave when it passes
through different media.
• Waves bend around barriers or through openings
during diffraction.
• The result of two or more waves overlapping is called
interference.
• Amplitude increases during constructive interference
and decreases during destructive interference.
• Resonance occurs when a vibrating object causes
another object to vibrate at one of its resonant
frequencies.
Reflection: Waves reflect after hitting
a barrier.
Refraction: The bending of a wave when it
passes through different media.
Diffraction: Waves bend around
barriers or through openings
The result of two or more waves
overlapping is called interference.
Amplitude increases during constructive
interference and decreases during
destructive interference.
Constructive & Destructive Interference
• PhET simulation
• Demonstration
Resonance
• Resonance occurs when a vibrating object
causes another object to vibrate at one of its
resonant frequencies.
• Tacoma Narrows Bridge
• Wine Glass
Practice
• Which of the following results in more energy
in a wave?
• A. a smaller wavelength
• B. a lower frequency
• C. a shallower amplitude
• D. a lower speed
Answer
• Which of the following results in more energy
in a wave?
• A. a smaller wavelength
• B. a lower frequency
• C. a shallower amplitude
• D. a lower speed
Practice
• Refraction occurs when a wave enters a new
medium at an angle because
• A. the frequency changes.
• B. the amplitude changes.
• C. the wave speed changes.
• D. the new medium changes.
Answer
• Refraction occurs when a wave enters a new
medium at an angle because
• A. the frequency changes.
• B. the amplitude changes.
• C. the wave speed changes.
• D. the new medium changes.
Practice
• The bending of a wave as it passes at an angle
from one medium to another is called
• A. reflection.
• B. refraction.
• C. diffraction.
• D. interference.
Answer
• The bending of a wave as it passes at an angle
from one medium to another is called
• A. reflection.
• B. refraction.
• C. diffraction.
• D. interference.
Sound
• All sounds are generated by vibrations.
• Sounds travel as longitudinal waves consisting of
compressions and rarefactions.
• Sound waves travel in all directions away from their source.
• Sound waves require a medium through which to travel.
Sound cannot travel in a vacuum.
• Your ears convert sound into electrical impulses that are sent
to your brain.
• Exposure to loud sounds can cause hearing damage.
• Using earplugs and lowering the volume of sounds can
prevent hearing damage.
Properties of Sound
• The speed of sound depends on the medium and the
temperature.
• The pitch of a sound becomes higher as the frequency of
the sound wave becomes higher. Frequency is expressed in
units of Hertz (Hz), which is equivalent to waves per
second.
• The Doppler effect is the apparent change in frequency of a
sound caused by the motion of either the listener or the
source of the sound.
• Loudness increases with the amplitude of the sound.
Loudness is expressed in decibels.
• The amplitude and frequency of a sound can be measured
electronically by an oscilloscope.
Sound requires a medium
• Alarm clock in a bell jar demo
How We Hear:
We lose the ability
to hear higher
pitches as we age.
Damage to any
part of the ear
can cause
deafness.
The speed of sound depends on the
medium and the temperature.
The pitch of a sound becomes higher
as the frequency of the sound wave
becomes higher.
The Doppler effect is the apparent
change in frequency of a sound caused
by the motion of either the listener or
the source of the sound.
Loudness increases with the amplitude
of the sound. Loudness is expressed in
decibels.