RIGHT PAGE 58
October 25
Focus: Sound and Hearing
Objective: Explain the relationship
among the rate of vibration, the
medium through which vibrations
travel, sound and hearing
EQ: How does sound travel?
HW: story about the eye, unit test
Thursday
Warm-Up: Review answer questions
WARM UP
ANSWER IN COMPLETE SENTENCES
1.What is the difference between a solid, a
liquid, and a gas?
2.Describe what the molecules are like in a
solid.
3.Describe what the molecules are like in a
liquid.
4.Describe what the molecules are like in a
gas.
5. What is sound?
Remember
What is a
solid?
A solid is any object where
the molecules are TIGHTLY
packed very close together.
What is a
liquid?
A liquid is any object where
the molecules are LOOSELY
packed.
What is a
gas?
A gas is any object where the
molecules are very far apart
and move around easily.
Sound …
Notes
1. Is a form of energy produced
whenever a body vibrates in a
medium.
2. It is transferred by vibrating
matter.
3.Vibrations travel from
molecule to molecule.
Vibration
- Back and forth movement of molecules
of matter
- For example,
At the end of activity:
You will be able to answer this question:
Which of the following materials
will sound travel through
fastest: air, water or wood?
Explain your answer.
HUMAN MOLECULES
Sound passes from one molecule to another
PREDICTION:
When molecules are close together, will
sound travel faster or slower?
When molecules are far apart, will sound
travel faster or slower?
HUMAN MOLECULES
Sound passes from one molecule to another
CONCLUSION:
Sound travels fastest through (solid,
liquid, gas) because….
Sound travels slowest through (solid,
liquid, gas) because…..
Molecules close together = easier for sound
to move
Molecules far apart = harder for sound to
move
Now Answer:
Which of the following materials
will sound travel through
fastest: air, water or wood?
Explain your answer.
•Tuning forks create sound by compressing
the air around them.
•These compressions vibrate air molecules
as they travel away from the fork.
•Sound requires molecules to vibrate. No
molecules, no sound.
http://player.discoveryeducation.com/index.
cfm?guidAssetId=790A7AA9-4409-47CAB8B3-35FF519C5E94
Sound travels through different media.
We hear sound which usually travels through air. Sound
travels through other media as well, such as water and
various solids.
Sound travels different speeds in different media. Sound
typically travels faster in a solid that a liquid and faster in
a liquid than a gas.
The denser the medium, the
faster sound will travel.
The higher the temperature, the
faster the particles of the
medium will move and the faster
the particles will carry the sound.
Cornell Notes
What is the The eardrum is the part of
eardrum? the ear that senses sound
waves.
Eardrum
Cornell Notes
What is
The cochlea is the part of your
the
ear that detects vibrations and
cochlea? sends a message to your brain.
Pathway
to the
Brain
Cochlea
Eardrum
Cornell Notes
How are
sound
waves
heard?
Sound waves vibrate the
eardrum. The vibrations move into
the cochlea and then into your
brain.
Pathway
to the
Brain
Cochlea
Eardrum
Cornell Notes
What is
loudness?
Loudness is how loud a sound
wave is. Loudness comes from
the AMPLITUDE of a wave.
Cornell Notes
What is
pitch?
Pitch is the tone of the sound
wave. Pitch is determined by
the FREQUENCY of a wave.
http://id.mind.net/~zona/mstm/physics/waves/introduction/introductionWaves.html
Example #1
Which wave is louder?
Which wave is softer?
1
2
Wave A is louder.
A
1
B
0
0
-1
-2
5
Wave B is
softer.
10
15
Example #2
Which wave is louder?
Which wave is softer?
2
2
Wave B is louder.
B
1
A
0
0
-1
-2
5
Wave A is
softer.
10
15
Example #3
Which wave is the loudest?
Which wave is the softest?
3
2
Wave A is the
loudest.
A
B
C
1
0
0
-1
-2
5
Wave C is
the softest.
10
15
Example #4
Which wave has a higher pitch?
Which wave has a lower pitch?
4
2
A
1
Wave A has a
higher pitch.
B
0
0
-1
-2
5
Wave B
has a lower
pitch.
10
15
Example #5
Which wave has a higher pitch?
Which wave has a lower pitch?
5
2
B
1
Wave B has a
A higher pitch.
0
0
-1
-2
5
Wave A
has a lower
pitch.
10
15
Example #6
Which wave has the highest pitch?
Which wave has the lowest pitch?
6
2
A
1
B
C
Wave A has the
highest pitch.
0
0
-1
-2
5
Wave C
has the
lowest
pitch.
10
15
Example #7
Which wave is louder?
Which wave has the lowest pitch?
7
2
A
Wave A is louder.
B
1
0
0
-1
-2
5
Wave B
has the
lowest
pitch.
10
15
Example #8
Which wave has the highest pitch?
Which wave is softer?
8
2
Wave A has the
highest pitch.
B
1
A
0
0
-1
-2
5
Wave A is
softer.
10
15
Example #9
Which wave has the highest pitch?
Which wave is softer?
9
2
Wave B has the
highest pitch.
B
1
C
0
0
-1
-2
5
Wave C is
softer.
10
15
Example #10
Which wave has the highest pitch?
Which wave is the softest?
10
2
Waves A and B
have the same
pitch.
A
1
B
0
0
-1
-2
5
Wave B is
the softest.
10
15
Comparing Waves
Let’s go back and write comparison
statements for each example.
Comparison statements answer this
question:
What is Wave A’s amplitude
and pitch compared to Wave
B?
Let’s Recap!
Look at Size of wave (how high and how
low)  Amplitude of Wave
 Loudness of Sound
Look at the Number of Humps of Wave
 Frequency of Wave
 Pitch of Sound
Example #4
What is wave A’s loudness and pitch in
comparison to wave B?
4
2
A
1
B
0
0
-1
-2
5
10
Wave A is the same
loudness as Wave B
because the
amplitude is the
same.
Wave15A has a higher
pitch than Wave B
because it has a
higher frequency
than Wave B.
Example #7
What is wave A’s loudness and pitch in
comparison to wave B?
7
2
Wave A is louder
than Wave B
because it has a
higher amplitude
than Wave B.
A
B
1
0
0
-1
-2
5
10
Wave15A has a higher
pitch than Wave B
because it has a
higher frequency
than Wave B.
Example #9
What is wave C’s loudness and pitch in
comparison to wave B?
9
Wave C is softer than
Wave B because it has
a lower amplitude than
Wave B.
2
B
1
C
0
0
-1
-2
5
10
Wave15C has a lower
pitch than Wave B
because it has a
lower frequency
than Wave B.
Exit Ticket
What is Wave A’s loudness and pitch
compared to Wave B? Explain your answer!
2
B
1
A
0
0
-1
-2
5
10
15