# types of sound waves

```HOW TO IDENTIFY TYPES OF WAVES
•In a transverse wave, the particles are displaced
perpendicular to the direction the wave travels.
•Examples of transverse waves include vibrations
on a string and ripples on the surface of water.
Figure 1: The parts of the slinky in a transverse wave move vertically up and down while
the wave disturbance travels horizontally.
HOW TO IDENTIFY TYPES OF WAVES
•In a longitudinal wave the particles are
displaced parallel to the direction the wave
travels.
•An example of longitudinal waves is
Figure 2: The parts of the slinky in a longitudinal wave and the
wave disturbance travel horizontally.
COMMON MISTAKES AND MISCONCEPTIONS
•Sometimes people forget
wave speed isn't the same as
the speed of the particles in
the medium.
COMMON MISTAKES AND MISCONCEPTIONS
•The wave speed is how
quickly the disturbance
travels through a medium.
COMMON MISTAKES AND MISCONCEPTIONS
•The particle speed is how
quickly a particle moves
position.
•A certain sound wave traveling in the air
has a wavelength of 322 nm when the
velocity of sound is 320 m/s. What is the
frequency of this sound wave?
F represents frequency,
V represents the velocity of the
wave, and
Λ represents the wavelength of
the wave.
convert the wavelength into
meters, if necessary.
If the wavelength is given in
nanometers, you need to
convert this value into meters
by dividing it by the number of
nanometers in a single meter.
Divide the velocity by the
wavelength.
Divide the velocity of the
wave, V,
by the wavelength converted
into meters, λ,
in order to find the frequency, f.
After completing the previous
step, you will have completed
frequency of the wave.
which is the unit for frequency.
VOCABULARY
•Intensity – the amount of energy an sound wave
carries per second through a unit area. Measured in
watts per meter squared. W/m&sup2;
• Example – when a sound wave carries a large amount of
energy, the molecules of the medium move a greater distance
as the wave pass by, and the sound has a greater amplitude
VOCABULARY
•Loudness – sound level, describes what you actually
hear. A sound wave of greater intensity sounds
louder
•Decibels (db) – measures loudness.
A sound you can
barely hear is 0 db. 100db can damage your ears.
INTENSITY DETERMINES LOUDNESS.
A sound wave with a higher amplitude and energy
is perceived as a louder sound.
EQ: How does intensity, loudness, frequency
and pitch affect sound waves?
SECTION
OUTLINE
INTENSITY DETERMINES LOUDNESS.
A sound wave with a lower amplitude and energy
is perceived as a softer sound.
EQ: How does intensity, loudness,
frequency and pitch affect sound
waves?
VOCABULARY
FREQUENCY – THE NUMBER OF VIBRATIONS THAT OCCUR PER SECOND IN A SOUND WAVE.
MEASURED IN HERTZ. A FREQUENCY OF 50HZ MEANS 50 VIBRATIONS PER SECOND.
• WE HEAR SOUNDS WITH FREQUENCIES THAT ARE BETWEEN 20HZ AND 20,000HZ
ULTRASOUND – SOUND WAVES WITH FREQUENCIES ABOVE THE NORMAL RANGE OF
HEARING
INFRASOUND – SOUND WAVES WITH FREQUENCIES BELOW THE HUMAN RANGE OF
HEARING
EQ: How does intensity,
loudness, frequency and pitch
affect sound waves?
VOCABULARY
• PITCH – A DESCRIPTION OF HOW HIGH OR HOW LOW A SOUND SEEMS TO A PERSON.
• PITCH DEPENDS ON THE FREQUENCY OF A SOUND WAVE
• HIGH FREQUENCY MEANS HIGH PITCH
• LOW FREQUENCY MEANS LOW PITCH
EQ: How does intensity, loudness, frequency and
pitch affect sound waves?
FREQUENCY DETERMINES PITCH.
A sound wave with a lower frequency and longer
wavelength is perceived to have a lower pitch.
A sound wave with a higher frequency and shorter
wavelength is perceived to have a higher pitch.
EQ: How does
intensity,
loudness,
frequency and
pitch affect
sound waves?
PIANO EXAMPLE OF PITCH
TENSION - A TIGHTER STRING PRODUCES A HIGHER FREQUENCY. THEREFORE YOU HEAR THE SOUND AT A
HIGHER PITCH.
LENGTH OF THE STRING - RIGHT SIDE OF THE PIANO HAS HIGHER PITCH, SHORTER STRING. LEFT SIDE OF
PIANO HAS LOWER PITCH, LONGER STRING
THICKNESS OF A STRING – THICKER MEANS LOWER PITCH
EQ: How does intensity, loudness, frequency and
pitch affect sound waves?
VOCABULARY
• RESONANCE – WHEN THE FREQUENCY OF THE SOUND WAVE EXACTLY MATCHES THE FREQUENCY OF AN
OBJECT
EQ: How does intensity, loudness,
frequency and pitch affect sound waves?
DOPPLER EFFECT
THE APPARENT CHANGE IN FREQUENCY AS A WAVE SOURCE MOVES IN RELATION TO THE LISTENER
EQ: How does
intensity,
loudness,
frequency and
pitch affect
sound waves?
EQ: How does
intensity, loudness,
frequency and pitch
affect sound
waves?
DOPPLER EFFECT
• AS A SOUND SOURCE MOVES TOWARD THE LISTENER, THE WAVES REACH THE LISTENER WITH A HIGHER
FREQUENCY. THE PITCH APPEARS TO INCREASE BECAUSE OF THE DOPPLER EFFECT
CLASS WORK AND HOMEWORK
FILL IN
• WHAT DID I LEARN
• CONFUSED
• SAY
• READ PAGES O 46 – O 51.
• QUESTIONS 1-6, P. O 51
• 2-2 WORKSHEET
EQ: How does
intensity, loudness,
frequency and pitch
affect sound waves?
```