Transcript Sound & Palm Pipes

Palm Pipes
Objective
Students will be able to create
vibrations, which we hear as music,
in order to understand basic
properties of sound and waves.
Warm up
Using the slinky on your table,
demonstrate the movement of a
sound wave.
Now demonstrate the movement of
a light wave.
Focus Questions
 What are some important
properties of sound waves?
 What is resonance and why
is it important?
 What is sound and how do
we hear it?
 What is music and how do
we make music?
Exploration
Palm Pipes
http://www.stevespanglerscience.com/img/cache/02268c260f8fff6f7502dd93a20e39be/WPVC-100_2.jpg
Palm Pipes
 Check to see the note of your palm
pipe.
 Follow along with the music and play
your palm pipe when your note
occurs.
Mary Had a Little Lamb
Melody
E D C D E E ED D D E G G
(1st line)
Melody
(2nd line) E D C D E E E E D D E D C
HAPPY BIRTHDAY
Melody C C D C F E
Harmony
A
A Bb
Melody C C C A F E D
Harmony
F
C Bb
C C D CGF
Bb
B A
b
Bb Bb A F G F
C
A
Jingle Bells
Melody E E E E E E E G C D E
Harmony F F F F F E E E E E D D E D G
Melody E E E E E E E G C D E
Harmony F F F F F E E E E G G F D C
GOD BLESS AMERICA
Melody
F E D E D C
Harmony A C
Harmony
Melody
E
E D E F
Bb A C F G A
Melody
C
E F G C
Harmony C
E
G A Bb D
G F G A
D
G F G F E F
F
E
C
F GA C
G A Bb E A Bb C
D
E
F
Melody
D C Bb A G F
Bb A G F
Harmony
F F E C E D
F F E C
G C
G
TWINKLE, TWINKLE LITTLE STAR
F F C C D D C
Bb Bb A A G G F
Harmony C C A A Bb Bb A
G G F F E E C
C C Bb Bb A A G
C C Bb Bb A A G
Harmony A A G G F F C
A A G G F F C
Melody
Melody
F F C C D D C
Bb Bb A A G G F
Harmony C C A A Bb Bb A
G G F F E E C
Melody
Explanation
 How could pipes that have the
same note be different lengths?
Explanation
How does it work?
 When you pound the Palm Pipe into the palm of your
hand, it disturbs the air molecules inside the tube. The
action of these molecules creates the vibration that
becomes the note you hear.
 The different lengths of pipe create different lengths of
sound waves, which in turn create eight different notes.
Explanation
Click this picture for the online wave animation.
Explanation
http://www.passmyexams.co.uk/GCSE/physics/images/long_waves.jpg
Explanation
Wavelength is the distance from the crest of one wave to the crest of
the next.
Frequency is the number of waves that pass a point in each second.
Amplitude this is the measure of the amount of energy in a sound
wave.
http://www.fi.edu/pieces/dukerich/vibrations/graphics/wavedi.gif
Explanation
This is how a high and a low soundwave looks.
A bird makes a high pitch.
A lion makes a low pitch.
Can you think of other high and low pitched sounds?
Explanation
Basic characteristics of standing waves
 Node
 Points where the string does not move
 Anti-node
 Points where the string moves the
most
Explanation
RESONANCE
 A condition where a force (a push) occurs at a
frequency that results in a Standing Wave
 These Standing Waves occur at what are called
Natural Frequencies or Harmonics.
 Every object, substance and material has its own
Natural Frequencies, where they “like” to vibrate.
Explanation
FREQUENCY x WAVELENGTH
 Each Harmonic has a different frequency and
wavelength
 Frequency x Wavelength gives the same answer
for ALL Harmonics
 Cycles/Seconds x Meters/Cycle= Meters/Second
which is a value for speed of the Wave on the
string
 If Frequency increases, Wavelength decreases
and if Frequency decreases, Wavelength increases
Explanation
Sound Waves
 How do we perceive Sound Waves?
 What do they have in common with other kinds
of waves?
 What is different about Sound Waves?
Explanation
Sound and Music - Chords
 Different notes have different frequencies.
 Chords are combinations of different notes with
specific mathematical relationships.
 Different relationships of the notes will produce
chords with very different “moods” or “feel.”
Explanation
Musical Instruments
 Musical instruments play different notes
 Frequencies are controlled by altering
wavelength
 Vibrating materials like strings or reeds
cause chunks or columns of air to vibrate
Explanation
Musical Instruments
 Natural Frequencies/Harmonics cause amplification
through Resonance
 Instruments can be amplified this way and/or
electronically
 The vibrating element vibrates at ALL its Harmonics, not
just the Fundamental.
 The combination of these frequencies give an instrument
its particular sound.
Elaboration
Important numbers:
 Speed of sound in air at room temperature
= 350 m/s.
 Speed of light in a vacuum (in outer space)
= 299,792,458 m/s or 3.0 x 108
Frequency calculations
 Velocity of a sound wave is equal to its frequency
times its wavelength.
v = f x λ
1. wavelength can be
obtained by
multiplying the tube
length in meters by 4
2. velocity is
350m/s in normal
room air
temperature
3. So…if you divide 350m/s by a
tube's wavelength value, you obtain
the approximate frequency in cycle
per second, or hertz, of the note the
tube will produce.
Example:
350 m/s
tube length of 21 cm (.21 m) x 4= .84 m
= frequency of 416 Hz
Frequency calculations:
 Now calculate the frequency of the Palm Pipes
assigned to the members of your group and be
prepared to share your answers with the class.
Approximate answers:
Note
Length (cm)
Frequency (Hz)
F1
23.6
349
G1
21.0
392
A1
18.7
440
B flat 1
17.5
446
C1
15.8
523
D1
14.0
587
E1
12.5
659
F2
11.8
698
G2
10.5
784
A2
9.4
880
B flat 2
9.2
892
C2
7.9
1046
D2
E2
7.0
6.2
1174
1318
F3
5.9
1397
Closure
In your notes, write a brief
summary of what you have
learned.