palm pipes. objective students will be able to create vibrations, which we hear as music, in order...
TRANSCRIPT
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 QuestionsWhat 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 PipesCheck 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 LambMelody
(1st line)
E D C D E E E D D D E G G
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 C C D C G F
Harmony A A Bb Bb BbA
Melody C C C A F E D BbBb A F G F
Harmony F C Bb 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 G F G A G A Bb D
Harmony A C E E D E F D
Melody Bb A C F G A G F G F E F
Harmony C F E C
Melody E F G C F G A C G A Bb E A Bb C
Harmony C E D F E G C G
Melody D C Bb A G F Bb A G F
Harmony F F E C E D F F E C
TWINKLE, TWINKLE LITTLE STARMelody 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 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 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
Explanation
How could pipes that have the same note be different lengths?
ExplanationHow 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
http://www.fi.edu/pieces/dukerich/vibrations/graphics/wavedi.gif
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.
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?
Basic characteristics of standing waves
NodePoints where the string does not move
Anti-nodePoints where the string moves the
most
Explanation
RESONANCEA condition where a force (a push) occurs at a
frequency that results in a Standing WaveThese 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 WAVELENGTHEach Harmonic has a different
frequency and wavelengthFrequency x Wavelength gives the
same answer for ALL HarmonicsCycles/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 - ChordsDifferent 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 InstrumentsMusical instruments play different
notesFrequencies are controlled by altering
wavelengthVibrating materials like strings or reeds
cause chunks or columns of air to vibrate
Explanation
Musical InstrumentsNatural Frequencies/Harmonics cause amplification
through ResonanceInstruments can be amplified this way and/or
electronicallyThe vibrating element vibrates at ALL its Harmonics, not
just the Fundamental.The combination of these frequencies give an instrument
its particular sound.
Explanation
Elaboration
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
Important numbers:
Frequency calculationsVelocity of a sound wave is equal to its
frequency times its wavelength.
v = f x λ
2. velocity is 350m/s in normal room air temperature
1. wavelength can be obtained by multiplying the tube length in meters by 4
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 7.0 1174
E2 6.2 1318
F3 5.9 1397
Closure
In your notes, write a brief summary of what you have learned.