This is a demonstration of what
wave phenomenon…
Resonance
Can sound waves travel in a
vacuum?
NO, they need a medium to travel
through.
The distance between one waves
crest and the next waves crest is
called a ___________.
wavelength
For each second you count
between lightning and the
thunder it produces, how far
away does it mean the lightning
is from you?
340 meters
About 1/5th of a mile
 Or about 1/3rd of a kilometer

Noise cancelling headphones are
an example of ________
interference.
Destructive
What causes a tsunami?
An underwater earthquake

OR a massive landslide
If an ambulance is headed
toward you the frequency of the
sound waves coming toward you
is ________ than normal.
Higher frequency

Shorter wavelength
The frequency of the sound
coming from that same
ambulance would be ________
than normal as it moves a way
from you
Lower frequency

Higher wavelength
A wave travels a distance of 20
meters in a time of 4 seconds,
what is the speed of the wave?
5 m/s
Which of these would sound
travel the fastest through
Salt water
 Fresh water
 A wood cabinet
 A steel beam

Steel beam, because it is the
most rigid
Is there sound in outer space?
NO, space is a vacuum and
sound needs a medium to travel
through
On a standing wave, the points
that do not move are referred to
as…..
Nodes
The number of times a wave
vibrates each second is referred
to as _______
frequency
The amount of time it takes each
wave to pass is referred to as
_______
Period
What type of wave is a sound
wave?
Longitudinal wave
Waves in the ocean are what type
of wave
Transverse
What is the proper unit for
frequency?
Hertz
An oceanic depth-sounding
vessel surveys the ocean bottom
with ultrasonic sound that travels
1530 m/s in seawater, and finds
a 10-second time delay of the
echo to the ocean floor and
back. The ocean depth there is
7650 meters
Beats are produced by two tuning
forks that are sounded together,
if one tuning fork has a frequency
of 300 Hz and the other has a
frequency of 305 Hz, what will be
the frequency of the beats they
produce?
5 Hz

Difference between frequencies
What destroyed the Tacoma
Narrows bridge?
Resonance/ Standing Wave

A standing wave was created when the
bridge resonated at its natural frequency
as caused by the wind.
A 680 Hz sound wave that travels
through air at a speed of 340
m/s would have a wavelength
of____?
.5 meters
V = fλ
 So λ = v/ f or 340 / 680

12 full waves pass a dock in a
time of 6 seconds.

A) what is the frequency of the waves?

B) What is the period of the waves

A) 2 Hz

B) .5 seconds
A skipper on a boat notices wave
crests passing the anchor chain
every 6 seconds. The skipper
estimates the distance between
crests at 30 m. What is the
speed of the water waves?
In what kind of situation(s) would
the doppler effect occur?
If a source of sound waves is
moving toward you or away from
you
If the frequency of a set of waves
is increased, what will happen to
wavelength?
It will go down

Inverse relationship
What of these wave properties
determines the pitch of a sound
wave?
Frequency
 Wavelength
 Period
 Speed

Frequency

High frequency  high pitch
What is the source of all wave
motion?
Vibration
A wave created by shaking a rope
up and down is called a ______
wave.
Transverse
A wave has a wavelength of 1.5
meters. During a single period
this wave has travelled how far?
1.5 meters
The amplitude of a wave is 3.0
meters, the top to bottom
distance of the disturbance
would be
6 meters
What property of a wave
determines loudness?
Amplitude
Two waves that are in-phase with
each other will undergo _______
interference.
Constructive
New larger wave will be produced
 Amplitudes add together

The phenomenon of ‘beats’
results from which of these
Interference
 Diffraction
 Frequency modulation
 resonance

interference
T or F. We would hear a sonic
boom the instant a supersonic
plane flew overhead.
False, it would be after the plane
was directly overhead because
the planes sound is trailing it
T or F. Resonance occurs when
an object vibrates at its natural
frequency
True

Every elastic object has its own natural
frequency, when it vibrates at that
frequency a large increase in amplitude
will happen
A certain ocean wave has a
frequency of 10 hertz and a
wavelength of 3 meters. What is
the wave’s speed?
30 m/s
The period of a wave is 8
seconds, what is its frequency?
1/8 Hz
How do we use the Doppler
Effect to tell us that the universe
is still expanding?

All galaxies are ‘red-shifted’ meaning
they have longer wavelengths of light,
this tells us they are all moving away
from us…. Universe is expanding
If you have created a standing
wave with a slinky and increase
the frequency with which you are
shaking the slinky what will
happen to the number of waves
in the slinky?
Number of waves will increase

Wavelength of each wave will decrease
 more waves crammed into the same
length
The regions in between the
compressed regions of a sound
wave are called _________.
Rarefactions
The amplitude of a water wave is .5
meters. If a raft has one full wave pass
under it… through how much distance will
it vibrate?
2 meters

4 amplitudes
How is a sonic boom formed?

Something moving faster than the speed
of sound
What other than a jet-powered
vehicle can create a sonic boom?
Crack of a whip
What does ‘ultrasonic’ mean?

Sound waves that have a frequency
higher than that which is audible >20,000
Hz.