Waves
Mrs. Quinn
Spring 2010
Wave
 A disturbance that
transfers energy
through matter or
space
 When a wave moves
through matter, the
particles of matter do
NOT move along with
the wave.
 Only the energy that
produces the wave
moves with the wave.
http://oraclespeak.files.wordpress.co
m/2009/12/wave.jpg
Example of Waves
http://mendocoastcurrent.files.wordpress.com/2008/12/wave-oceanblue-sea-water-white-foam-photo.jpg
http://www.physicalgeography.net/fundamentals/im
ages/epicenter.gif
http://hclibrary.org/teachernotes/wpcontent/uploads/image/sound_wave.jpg
http://www.abc.net.au/science/features/
quantum/img/wave.jpg
Medium
 Any substance or
region through
which a wave is
transmitted
 A medium transfer
wave energy but
has no overall
movement itself
energy is
transmitted, but
matter is not.
http://odin.physastro.mnsu.edu/~eskridge/ast
r101/Surface_waves.jpg
2 Properties of a Medium that
Affect the Speed of a Wave
1. Density
 As density of medium increases,
speed of a wave decreases.
2. Elasticity
 This refers to the ability of a medium
to return quickly to its original shape
after being disturbed.
 More elastic, the faster the wave.
Example of Mediums
 Water  Ocean Waves
 Air
 Sound Waves
 All phases of Matter can act as a
medium.
 Light does not need a medium it can
be transmitted through a vacuum.
Review Questions
 1. How does a wave move through a
medium?
 2. What are the 2 properties affect
the speed of a wave?
 3. At 25 degrees Celsius, the speed of
sound in the 346 m/s. At zero
degrees, the speed of sound in air is
332 m/s. Explain why the speed
decrease as the temperature
decreases?
Types of Waves
 Wave are classified according to the
motion of the medium as compared
to the movement of the wave.
Types of Waves
1. Transverse

A wave in the
which the motion
of the medium is
at right angles to
the direction of
the wave.
http://media.tiscali.co.uk/imag
es/feeds/hutchinson/ency/c02
631.jpg
Types of Waves
 Longitudinal
 A wave that consists of a series of
compression and rarefactions.
 The motion of the medium is parallel
to the direction of the wave.
Motion of the
Medium back and
fourth.
http://www.passmyexams.co.uk/GCSE/physics/i
mages/long_waves.jpg
Compression
http://www.physicsclassroom.com/class/
sound/u11l1c.cfm
Compression
 A space in the medium in which the
molecules are crowded together.
Rarefaction
 A space in the medium in which there are
fewer molecules.
http://www.lcse.umn.edu/specs/labs/i
mages/rarefaction_spring.gif
Review Questions
 1. What are the 2 types of waves?
 2. Which type of wave is an ocean
wave?
 3. Which type of wave is a sound
wave?
Review Questions
4. Suppose that a long line of people
formed outside a movie theater and
a person at the end of the line
pushes the person in front of him.
Everyone in line moves forward and
then as people regain their balance
then move back again. Which type
of wave is generated? Why?
http://gilmore2.chem.northwestern.edu/images2/e_
simple1.gif
Characteristics of Waves
 Amplitude
 Wavelength
 Frequency
Amplitude
 The maximum
distance the molecules
of a medium are
displace from their rest
potential.
 Indicates the energy of
the wave.
 As energy increases,
amplitude increases.
http://schools.utah.gov/curr/science/cor
e/8thgrd/sciber8/forces/html/WAVENR
GY.HTM
Wavelength
 The distance
between 2
consecutive crests
or troughs
 Measured in
meters or
centimeters
Frequency
 The number of
complete waves, or
complete cycles
per unit of time.
 Measured in Hertz
(Hz)
http://www.qrg.northwestern.edu/projects/vss/docs/
media/Communications/frequency.gif
Website
 http://library.thinkquest.org/19537/ja
va/Beats.html
 This is a hyperlink, just click on it.