Waves
Waves are everywhere. Sound waves, visible light waves,
radio waves, microwaves, water waves, sine waves, cosine
waves, earthquake waves, waves on a string, and slinky
waves and are just a few of the examples of our daily
encounters with waves.
Waves

A wave can be described as a disturbance
that travels through a medium from one
location to another location.
The Nature of a Wave

Consider the slinky
– When a slinky is stretched from end to end and is held
at rest, it assumes a natural position known as the
equilibrium or rest position.
The Nature of a Wave

Consider the slinky
– To introduce a wave into the slinky, the first coils are
displaced or moved from its equilibrium or rest
position. The coils might be moved upwards or
downwards, forwards or backwards; but once moved, it
is returned to its original equilibrium or rest position.
The Nature of a Wave

Consider the slinky
– The act of moving the first coils of the slinky in a given
direction and then returning it to its equilibrium
position creates a
the slinky.
in
The Nature of a Wave

Consider the slinky
– If the first coil of the slinky is given a single back-and-
forth vibration, then we call the observed motion of the
disturbance through the slinky a _________________.
A ________________ is a single disturbance moving
through a medium from one location to another
location.
The Nature of a Wave

Consider the slinky
– The repeating and periodic disturbance which moves
through a medium from one location to another is
referred to as a wave.
– A _______________________ is a substance or
material which carries the wave.
– Waves are said to be an
___________________________________________
Types of Waves

A
wave is a wave in
which particles of the medium move in a direction
perpendicular to the direction which the wave
moves.
Slinky Demo
Types of Waves

A
wave is a wave in
which particles of the medium move in a direction
parallel to the direction which the wave moves.
Slinky Demo
Types of Waves

A
wave is a wave in which
particles of the medium undergo a circular motion.
Surface waves are neither longitudinal nor
transverse.
Video in 3 slides
Surface Wave

Water Waves
– A wave moving across the surface of an ocean, lake,
pond or other body of water. The waves are created by
some form of a disturbance, such as a rock thrown into
the water or a boat moving through the water. The
water wave has a crest and a trough and travels from
one location to another.
Surface Wave

In longitudinal and transverse waves, all the
particles in the entire bulk of the medium move in
a parallel and a perpendicular direction
(respectively) relative to the direction of energy
transport. In a surface wave, it is only the particles
at the surface of the medium which undergo the
circular motion.
Surface Wave

Another view
Properties of Waves
Properties of Waves

A Transverse Wave
– The _____________ of a wave is the point on the
medium which exhibits the maximum amount of
positive or upwards displacement from the rest
position. The _______________ of a wave is the point
on the medium which exhibits the maximum amount of
negative or downwards displacement from the rest
position.
Slinky Demo
Next
Properties of Waves

A Transverse Wave
– The ___________________ of a wave refers to the
maximum amount of displacement of a particle on the
medium from its rest position on a wave.
Slinky Demo
Properties of Waves

A Longitudinal Wave
– A ___________________ is a point on a medium
through which a longitudinal wave is traveling which
has the maximum density. The amplitude of a
longitudinal wave is a measure of how compressed the
medium becomes.
Slinky Demo
Next
Properties of Waves

A Longitudinal Wave
– A _____________________ is a point on a medium
through which a longitudinal wave is traveling which
has the minimum density.
Slinky Demo
Properties of Waves

Wavelength
– The ________________________ of a wave is simply
the length of one complete wave cycle.
Properties of Waves

Frequency
– The frequency of a wave is the number of complete
waves that pass a given point in a certain amount of
time.
– Frequency is expressed in Hertz (abbreviated Hz) where
1 Hz = 1 cycle/second.
Properties of Waves

Speed
– The speed of a wave is how far a wave travels in one
unit of time, or the distance divided by the time.
– Speed = Wavelength * Frequency
– Or…Frequency = Speed / Wavelength
Interaction of Waves
Interaction of Waves

___________________
– When a wave hits a surface through which it
cannot pass, it bounces back
Interaction of Waves

Angle of Incidence
– The angle of incidence is the angle between the
incoming wave and an imaginary perpendicular line to
the surface.
Interaction of Waves
Angle of Incidence.
The angle of reflection is the angle between the reflection
and the imaginary line.
Interaction of Waves

__________________
– is seen when a wave moves from one medium to
another at an angle, it changes speed as it enters the
second medium causing it to bend.
Aquarium Demo
Interaction of Waves
 _________________
– is seen when a wave passes a barrier or moves through
a hole in a barrier, it bends and spreads out.
Wave Tank Demo
Interaction of Waves
 Interference
– When two or more waves meet
Interaction of Waves
 ____________
Interference
– When two or more waves combine to make a wave with
a larger amplitude.
Interaction of Waves
 ______________
Interference
– When the amplitudes of two or more waves combine to
produce a wave with a smaller amplitude.
Making Waves

The Pan Flute
– A pan flute is a group of tubes with a closed end. Each
tube have a different length but, usually, the same
diameter of all other tubes.
– The length of the tube influence the pitch: longer tubes
produce lower notes, shorter tubes produce higher
notes.
– The inner diameter of the tube influence the speed of
blow needed to make the sound audible: smaller
diameter means less blow, greater diameter means more
blow.
Calculating WaveLength

Wavelength(ƛ) is equal to the speed of
sound(v) divided by the frequency(f) of the
sound.
– ƛ = v/f
v is in m/s, f is in Hz
– ƛ is in meters
– v = 346.65m/s (Around room temp)
Calculating Tube Length

First consider the tube, open on one end,
closed on the other…
Calculating Tube Length

The closed end would be a fixed point…like
where the strings attach on a guitar. The
open end would be the furthest the wave
could swing.
Calculating Tube Length

So, if I shrink it down……You can see that
what was in the tube was only about ¼ of a
whole wavelenght.
Calculating Tube Length

Therefore….the formula for calculating
tube length needs to be something like this.
– L=v/4xf
– Where L is in m,
– f is in Hz
– v = 346.65m/s (Around room temp)
Pentatonic Scales

The pentatonic scale consists of five notes
within one octave without any semitones or
tritones. Thus no clashing dissonant
intervals.
 the C major pentatonic (C - D - E - G – A)
Pentatonic Scales
Note
C
D
E
G
A
Frequency (Hz) Wavelength
(cm)
261.6
132
293.7
117
329.6
105
392.0
88.0
440.0
78.4