Transcript File

Warm-up
• No talking after the bell, have a pencil and
be ready to start class.
• List homework in your agenda.
• Read the new essential questions and
objective.
• Answer (predict) the following questions:
• How do we hear sound?
• How do we produce sound?
Warm-up
• No talking after the bell, have a
pencil and be ready to start
class.
• Complete your Ear flier
• Read over sound project
information.
• If everything is done read the
electromagnetic waves section
of your textbook (c-70)
Warm-up
• Think back to the lesson yesterday
when we discussed language
acquisition-Why do you think it is
so difficult for a deaf person to
learn proper speech? Do you
know the new innovation for deaf
babies that can help them develop
normal speech patterns? What is
it called?
Warm-up
Read page C 42 and 43 to answer these
questions.
1.What are some of the factors that can
affect the speed of sound?
2.Does sound travel at the same speed
through different mediums?
3.Why does sound travel the fastest in
solids?
4.Why does sound travel faster when the
temperature is higher?
1.What are some of the factors that can affect the
speed of sound? Temperature and the
medium it travels through (will not travel
w/o medium)
2.Does sound travel at the same speed through
different mediums? No approx. 344m/s in air,
1,400m/s in liquid, 5,000 through a solid.
3.Why does sound travel the fastest in solids? It’s
all about the density (how close together
are the atom/molecules).
4.Why does sound travel faster when the
temperature is higher? The bouncing air
molecules bump into each other more to carry the
sound energy.
Stations
• Station 1: Create a transverse wave with a slinky
and a rope, take turns doing and watching in your
group. Look at the pages about electromagnetic
waves (C 73-86) to see some types of transverse
waves.
• Station 2: Use the “telephones” to have
conversations, can you hear your partner through
the string?
• Station 3: Tuning forks-use the tuning forks to make
the salt “dance” and “sing”. Next play with
listening to them in your ear.
• Station 4: Create a longitudinal wave with a slinky,
take turns doing and watching in your group. Look
at the pages C 14-63 to see more about longitudinal
waves.
Warm-up
• Be ready for class with a pencil
and your warm-ups. Silent
focused thinking…What kind of
instrument are you planning to
create? How will you change the
pitch (frequency) of the sounds it
makes? The amplitude?
• When finished pick up the
essential waves handout and
complete it.
Warm-up
Take a mid check assessment and
answer sheet from the front table.
Do not start yet!!
Take out your homework from last
week “How doe we hear”
Be ready for class with a pencil and
have your name on the answer
sheet for the mid-assessment
change.
COPY THESE GOALS and Essential
questions from the board INTO YOUR
NOTEBOOK
Learning Goals:
1. Recognize that sound is a form of energy
caused by vibrations and in order to be
heard it must travel through solid, liquid or
gas.
2. Explain how the human ear works and
identify its parts that allow us to hear.
3. Explain how frequency, pitch, amplitude &
loudness are related.
4. Explain how the vocal cords work.
COPY THESE GOALS and Essential
questions from the board INTO YOUR
NOTEBOOK
Learning Goals:
1. Recognize that sound is a form of energy
caused by vibrations and in order to be
heard it must travel through solid, liquid or
gas.
2. Explain how the human ear works and
identify its parts that allow us to hear.
3. Explain how frequency, pitch, amplitude &
loudness are related.
4. Explain how the vocal cords work.
• 1. Read questions 1-6 and read the article called
“Your Ears” from Kidshealth.org and page in the
textbook as a reference to find the answers.
• 2. After reading think pair share with a partnerhave a meaningful conversation about what you
learned and what is unclear to you.
• 3. Create an informational flier (as a source of
notes) for the answers to the questions about the
ear and how we hear sound. Must have a title and
it is only the front page. Name and period on the
back.
• 4. Do not add color until all the information is
displayed on the flier. Only use the front side of a
piece of computer paper (fliers do not have a
back side). Add a title as well
Warm-up
• Which conducts sound
better: air or a solid?
Explain why.
Warm-up
• What is a medium?
• Is there a correlation between
how fast or slow sound waves
travel and the medium through
which they are traveling?
Sound and Vibrations
•Sound is created by vibrations.
•Vibration—a complete back and forth motion of
an object. Sound waves are longitudinal with
rarefaction and compression
• Sound Wave— a longitudinal wave caused by
vibrations and carried through a substance.
•All sound waves require a medium (plural, media).
•A medium is a substance through which a wave
can travel. Can be a solid, liquid, or gas.
Section 1
Sounds from a Stereo Speaker
Copyright © by Holt, Rinehart and Winston. All rights reserved.
How You Detect Sound
•Your ears change sound waves into
electrical signals that allow you to hear.
•http://www.innerbody.com/anim/ear.html
Sound waves
Parts of human ear—roll over the image
cochlea
http://health.howstuffworks.com/hearing.htm
The Human Ear
Middle Ear—
Hammer, Anvil,
& Stirrup
Auditory nerve—
Sends signals to
brain
Outer Ear— pinna & ear canal
Eardrum—separates
outer & inner ear,
sound waves pass
through to get to
middle ear.
Inner ear—
Cochlea with
liquid & hairs
Magnified Cochlear Hairs
Eardrums
Hearing Loss and Deafness
•If any part of the ear is damaged or does not
work properly, hearing loss or deafness may
result.
•Hearing Loss often results from long-term
exposure to loud sounds.
• Protecting Your Hearing
•Loud sounds can be blocked out by earplugs.
•listen at a lower volume when you are using
headphones.
•move away from loud sounds.
•Example: sit away from the speakers at a
concert.
How do the vocal cords work?
• The vocal cords are found in the
Larynx. Put several fingers in front of
your throat and hum-Do you feel the
vibrations in your throat? The vocal
cords tense up when you speak or singthe air being pushed up from the lungs
into the small opening of the vocal
cords makes them vibrate, which
produces sound waves.
The Speed of Sound
•The speed of sound depends only on the
medium in which the sound is traveling.
• How the Speed of Sound Can Change
•Sound travels quickly through air, but it travels
faster in liquids and even faster in solids.
•Temperature also affects the speed of sound.
In general, the cooler the medium is, the
slower the speed of sound.
Pitch and Frequency
The frequency of a sound determines
the pitch.
•Pitch—how low or high a sound seems
to be
•Frequency—the number of waves that
are made in a given time.
Pitch & Frequency
• The higher the frequency the higher
the pitch.
• The lower the frequency the lower the
pitch.
• Sounds that have a frequency too high
for people to hear are called ultrasonic.
• http://www.pbs.org/wgbh/nova/sciencenow/3204/04.html (NOVA
booming dunes) Booming dune sound ( bottom of page)
• http://www.chariho.k12.ri.us/curriculum/MISmart/ocean/sand5.ht
m
Section 2
Frequency and Pitch
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Pitch and Frequency
•The Doppler Effect is the apparent change in the
frequency (or pitch) of a sound caused by the
motion of either the listener or the source of the
sound.
•Example: a siren on an ambulance or police car
driving toward you seems to be at a higher pitch
than after it passes you
•Animations:
•http://www.surendranath.org/Applets/Waves/Doppler/DopplerApplet.html
•http://lectureonline.cl.msu.edu/~mmp/applist/doppler/d.htm
•http://www.soinc.org/events/crave/index2.htm
•http://www.kettering.edu/~drussell/Demos/doppler/doppler.html
•Train video demonstrating Doppler:
http://www.norcalscan.org/railroad/rfemov/trainmovie1_T1.mov
Section 2
The Doppler Effect
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Loudness and Amplitude
•The amplitude of a wave affects the
loudness of a sound.
•Loudness—a measure of how well a sound
can be heard
•The more energy used to create the sound
vibrations, the louder the sound will be
Loudness and Amplitude
• Using more energy causes air particles to
vibrate farther from their rest positions,
this gives the wave a larger amplitude.
• The larger the amplitude, the louder the
sound.
• The most common unit used to measure
loudness is the decibel (dB).
•
•
http://www.teachersdomain.org/resources/lsps07/sci/phys/energy/am
plitude/index.html (simulation and decibels (3rd slide)
Visual concepts: http://my.hrw.com/
“Seeing” Amplitude and Frequency
• Oscilloscope—A device used to graph
representations of sound waves.
•It changes a sound wave into an electrical
signal. The electrical signal is graphed on the
screen in the form of a wave.
End of Slide
Reflection of Sound Waves
• Echolocation—the process that uses reflected
sound waves to find (locate) objects
•Examples of uses of echolocation:
•Bats
•Fish finders on fishing boats
•Dolphins
•Sonar –technology used to locate objects
•Ultrasound (ultrasonography) medical
procedure used during pregnancy to see baby
•Remember an echo is a reflected sound wave.
Section 3
Echolocation
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section 3
How Sonar Works
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Resonance
•Resonance happens when an object vibrating at
or near a certain frequency causes a second
object to vibrate.
•Many musical instruments use resonance to
make sound.
•Examples:
•tuning fork causes salt on saran wrap to vibrate
•Drums in band room vibrate without being hit