Introduction to Waves
The location of energy sources
may be different than where they
are needed.
• The energy must be transferred from one
location to another by some means such
as……
Movement of Material
• Ie. Projectiles in flight,
wind, etc.
• When a ball hits a
window, the glass is
shattered by energy
transferred from the
ball during impact.
Thermal Convection
• Heat energy is
transferred by thermal
convection. This is
the movement of
quantities of heated
gas or liquid between
two locations.
Waves
• Ie. Sound waves, light
waves, water waves,
etc. The ideas and
language used to
describe waves are the
same, regardless of the
kinds of waves
involved.
What is a wave?
• The basic concept in the use of the term wave is
that the wave involves some quantity or
disturbance that changes in magnitude with
respect to time at a given location and changes in
magnitude from place to place at a given time.
• A wave is a disturbance that propagates through a
medium or space (vacuum).
Some waves are electromagnetic
waves
• Electromagnetic
waves can travel
through a material or
through a vacuum.
• Examples include
visible light,
microwaves, radio
waves, x-rays, infrared
rays and ultraviolet
waves.
• V = 3.00 x 108 m/s in
air or a vacuum
Some waves are mechanical
waves
• Mechanical waves require
a material medium for
their propagation
(movement).
• Sound waves, ocean
waves, and earthquakes
are mechanical waves.
• Mechanical waves can be
transverse, longitudinal, or
surface waves.
Transverse Waves
• A transverse wave is a
wave in which the
vibrations are at right
angles to the direction
of propagation.
• http://surendranath.trip
od.com/Applets/Wave
s/Twave01/Twave01A
pplet.html
Longitudinal Waves
• A longitudinal wave is
a wave in which the
vibrations are parallel
to the direction of
propagation of the
wave.
• http://www.glenbrook.
k12.il.us/GBSSCI/PH
YS/mmedia/waves/lw.
html
Surface Waves
• Surface waves such as
water waves combine
longitudinal and
transverse wave
movement.
•
http://www.classzone.com/books/earth_science/terc/
content/visualizations/es1604/es1604page01.cfm?cha
pter_no=visualization
Define the following wave terms
•
•
•
•
•
•
•
Elastic medium
Disturbance
Pulse
Crest
Trough
Compression
rarefaction
•
•
•
•
•
•
Speed
Frequency
Period
Wavelength
Amplitude
Phase