Learning Target 1: Describe the difference between mechanical and EM waves.
Define and differentiate between transverse and longitudinal waves.
MECHANICAL WAVES
 Must have a __________ and a __________ to
transport _______ from one location to another
 EXAMPLES: sound waves, slinky waves, water
waves, stadium waves, guitar strings, vocal cords

ELECTROMAGNETIC WAVES
Doesn’t need a medium to transport energy

Can travel through a _______ in empty space

EXAMPLES: light waves – radio, TV,
microwaves
TWO TYPES OF WAVES
Longitudinal:
Particles move
__________ to
the direction of
wave motion.
Transverse:
m
Particles move
___________
to the direction
of wave motion
Learning Target 2: Describe the characteristics of a wave (velocity, frequency, wavelength,
amplitude, and time period).
PARTS OF A WAVE
Transverse Wave




Crest: points on the wave corresponding to maximum ___________ displacement
Trough: points on the wave corresponding to maximum ___________ displacement
Wavelength ( ): __________ over which a wave repeats, in meters / the distance from one
crest to the next, or from one trough to the next
Amplitude ( ): vertical distance from _______________to crest or from equilibrium to trough,
in meters (energy of the waves)
Longitudinal Wave


Compression: correspond to _______________ pressure or density
Rarefaction: correspond to _______________ pressure or density
A FEW OTHER DEFINITIONS
 Wavelength ( ): The __________ a wave moves in 1 complete wave cycle, in __________.

Frequency ( ): How _________ a wave moves up and down.
The number of wave oscillations per second.
Measured in (# cycles)/second or 1/s or ________________.

Period ( ): The __________ for a wave to make 1 complete wave cycle
(oscillation).
Measured in ___________________.
Learning Target 3: Explain the relationship between velocity, frequency, wavelength, and
time period. Relate a wave’s speed to the medium in which it travels.
The Wave Equation:

(m/s) = (m) x (1/s)
Wave speed depends on the _____________!
*Same medium = Same speed
* EXAMPLE: Same air temperature / kind
of slinky / depth of water  Same speed!
See simulation to observe different medium, different speed: http://phet.colorado.edu/en/simulation/wave-on-a-string
SPEED OF A WAVE: How are frequency and wavelength related? They are ______________ of each
other. http://ngsir.netfirms.com/englishhtm/TwaveA.htm
___________ depends on the source. If _________ changes, the _______ changes so _____
has to change as well. For a given medium, if frequency increases then wavelength decreases (and
vice versa).

In 1 second of time:

* Large_____,small _____ v _______

* Small _______large _____ v_________
STANDING WAVES: Formed when a string is clamped at both ends. As a _________ (a single
disturbance) reaches one end, it gets _____________ back. If you keep sending those pulses, you get
a wave that appears to ______________________!
Parts to Label:
Nodes
Antinodes
http://www.youtube.com/watch?v=NpEevfOU4Z8&feature=related
http://www.youtube.com/watch?v=no7ZPPqtZEg&feature=related
Learning Target 4: Calculate the relationship between velocity, frequency, wavelength, and
time period.
EXAMPLES: 1) The water waves below are traveling with a speed of 2.5 m/s and splashing periodically
against Wibert’s perch. Each crest is 5 meters apart and splashes Wilber’s feet upon reaching his
perch. How much time passes between each successive drenching?
2) What is the wavelength of the radio waves broadcasting a station at 107.5 MHz if radio waves travel
at 3.0 x 108 m/s?
3) What is the speed of waves in a ripple tank if it is 20 cm from crest to crest and if two waves pass a
given location every 3 seconds?
MECHANICAL WAVES
 Must have a disturbance and a medium to
transport energy from one location to another
 EXAMPLES: sound waves, slinky waves, water
waves, stadium waves, guitar strings, vocal cords
ELECTROMAGNETIC WAVES

Doesn’t need a medium to transport energy

Can travel through a vacuum in empty space

EXAMPLES: light waves – radio, TV,
microwaves
TWO TYPES OF WAVES
Longitudinal:
Transverse:
Particles move
parallel to
the direction of
wave motion.
PARTS OF A WAVE
Transverse Wave




m

crest
A
troug
h
Crest: points on the wave corresponding to maximum upward displacement
Trough: points on the wave corresponding to maximum downward displacement
Wavelength (  ): Distance over which a wave repeats, in meters / the distance from one crest
to the next, or from one trough to the next
Amplitude ( A ): vertical distance from equilibrium to crest or from equilibrium to trough, in
meters
Longitudinal Wave

Particles move
perpendicular
to the direction
of wave motion
Compression: correspond to maximum pressure or density

Rarefaction: correspond to minimum pressure or density
A FEW OTHER DEFINITIONS
 Wavelength (  ): The distance a wave moves in 1 complete wave cycle, in meters.

f 
Frequency ( f ): How fast a wave moves up and down.
Measured in (# cycles)/second or 1/s or Hertz.
 Period ( T ): The time for a wave to make 1 complete wave cycle.
Measured in seconds per cycle
f 







T
#sec onds
cycle
1
T
SPEED OF A WAVE: How are frequency and wavelength related? They are inverses of each
other.
v  f

# cycles
sec ond
Wave speed depends on the MEDIUM!
*Same medium = Same speed

(m/s) = (m) x (1/s)
* EXAMPLE: Same air temperature / kind
of slinky / depth of water  Same speed!
f depends on the source. If medium changes, the v changes so  has to change as well.
For a given medium, if frequency increases then wavelength decreases (and vice versa).
In 1 second of time:
* Large  , small f, v same
* Small  , large f, v same
STANDING WAVES: Formed when a string is clamped at both ends. As a pulse (a single disturbance)
reaches one end, it gets reflected back. If you keep sending those pulses, you get a wave that appears
to stand still!
Parts to Label:
Nodes
antinodes
Antinodes
antinodes
nodes
EXAMPLES: 1) The water waves below are traveling with a speed of 2.5 m/s and splashing periodically
against Wibert’s perch. Each crest is 5 meters apart and splashes Wilber’s feet upon reaching his
perch. How much time passes between each successive drenching?
2) What is the wavelength of the radio waves broadcasting a station at 107.5 MHz if radio waves travel
at 3.0 x 108 m/s?
3) What is the speed of waves in a ripple tank if it is 20 cm from crest to crest and if two waves
pass a given location every 3 seconds?