WAVES
WAVES
Carries energy from one place to another
Classified by what they move through
1. Mechanical Waves
the energy is transferred by vibrations of medium
(medium = matter, stuff)
ex/ ocean waves move through water
2. Electromagnetic waves (EM Waves)
the energy moves through disturbances in the
electromagnetic field.
a disturbance that transfers energy
WAVE STRUCTURE
CREST (peak)
AMPLITUDE
middle to max peak
WAVELENGTH
TROUGH
WAVE STRUCTURE
Wavelength – the distance between
the same point in two waves.
Amplitude – the distance from the
middle of the wave to the
maximum crest or trough.
Frequency – The number of waves that pass a specific
point each second.
MECHANICAL WAVES
travel through & gradually
lose energy to that
medium
Examples:
water, sound, rope, &
spring waves
Mechanical Media:
water, air, rope, spring
require a medium (the material through which the wave is
moving) to transmit energy
Making a pulse
MECHANICAL WAVES
3 types:
Longitudinal
transverse
surface
TRANVERSE WAVES
Sideways or up & down
Examples:
S-type earthquake waves
Electromagnetic waves
(ex: light)
Vibration is perpendicular to the direction of
the motion of the wave
LONGITUDINAL WAVES
Back and forth (compression & rarefraction)
Also called compression or pressure wave
Examples:
P-type earthquake waves
Sound waves
Vibration is parallel to the
direction of the motion of the wave
Rarefraction (expansion)
Compression
SURFACE WAVES
Occur at the boundary between two different
mediums
Particles move more the closer they are to the
surface
Example:
Ocean waves
Vibration is circular
CHARACTERISTICS OF WAVES
Amplitude the distance from the
middle of the wave to the
maximum peak.
Frequency ƒ
the number of waves that pass a
specific point each second.
Wavelength the distance between
the same point in two waves.
Velocity vspeed = how fast the wave
travels
v = ƒ
AMPLITUDE
Distance between the “middle & crest” or “middle &
trough”
Gives indication of the
“power” of a wave
Does not affect the
velocity of a wave
Determines strength (earthquake), loudness (sound), or
brightness (electromagnetic wave)
WAVELENGTH Distance between any two
repeating points on a wave
crest-crest, trough-trough,expansion-expansion, compression-compression
Determines what colorswe see; what notes we hear (pitch)
Shorter wavelengths have a higher frequency because the waves aren’t as long
Frequency ƒ
measured in
wavelengths/second
Hertz (Hz) = number of
wavelengths in 1 second
the number of waves that pass a specific point each
second.
VELOCITY v the rate at which the
wave travels
Depends on medium
Mechanical waves travel
faster through dense
mediums
EM Waves are faster
through less dense
mediums
Which is a longitudinal wave, and which is a
transverse wave?
Which is a longitudinal wave, and which is a
transverse wave?
Which is a longitudinal wave, and which is a
transverse wave?
Which is a longitudinal wave, and which is a
transverse wave?
Which is a longitudinal wave, and which is a
transverse wave?
Earthquakes
Waves traveling through the ground.
P Wave: Primary wave. Moves lateral
Copyright © 2010 Ryan P. Murphy
P Wave: Primary wave. Moves lateral
Copyright © 2010 Ryan P. Murphy
P Wave: Primary wave. Moves lateral
Copyright © 2010 Ryan P. Murphy
P Wave: Primary wave. Moves lateral
Copyright © 2010 Ryan P. Murphy
P Wave: Primary wave. Moves lateral
Copyright © 2010 Ryan P. Murphy
S Wave: Secondary waves. Stronger and
moves up and down.
Copyright © 2010 Ryan P. Murphy
S Wave: Secondary waves. Stronger and
moves up and down.
Copyright © 2010 Ryan P. Murphy
S Wave: Secondary waves. Stronger and
moves up and down.
Copyright © 2010 Ryan P. Murphy
S Wave: Secondary waves. Stronger and
moves up and down.
Copyright © 2010 Ryan P. Murphy
S Wave: Secondary waves. Stronger and
moves up and down.
Copyright © 2010 Ryan P. Murphy
Wave reflection.
Copyright © 2010 Ryan P. Murphy
Wave reflection.
Reflection occurs when waves change
directions as a result of "bouncing off" a
surface like a mirror.
Copyright © 2010 Ryan P. Murphy
Wave reflection.
Reflection occurs when waves change
directions as a result of "bouncing off" a
surface like a mirror.
Copyright © 2010 Ryan P. Murphy
Wave reflection.
Reflection occurs when waves change
directions as a result of "bouncing off" a
surface like a mirror.
Copyright © 2010 Ryan P. Murphy
Refraction: The bending of a wave when it
enters a medium where its speed is
changed.
Copyright © 2010 Ryan P. Murphy
An birds must compensate for refraction
when catching fish.
Copyright © 2010 Ryan P. Murphy
Wave diffraction
A change in the direction of a wave as they
pass through an opening or around an object
in their path
Waves can be absorbed by objects and converted into other types of energy.Light waves can be absorbed by objects and in most cases the energy is converted into heat.
Wave interference.
Two waves can interact with one another, this
interaction is called interference.
Constructive Destructive
Wave interference.
Copyright © 2010 Ryan P. Murphy