1. Warm Up
Stand up paddle boards
(SUP’s) were first used
by pacific islanders to
travel between nearby
islands. Why bother with
paddling? Why not just
surf waves the whole
way across like a rad
surfer dude?

2. Defining Waves
 Wave: A repeating
disturbance (vibration) that
moves through a medium
carrying energy from one
location to another.
 Medium: a substance or
material that carries the
wave.
A Wave Transports Energy
and Not Matter

3. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? NOT A WAVE

4. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? WAVE

5. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? NOT A WAVE

6. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? WAVE

7. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? WAVE

8. Quick Quiz: Would this be a
wave?
 Is there an initial
disturbance, or energy
input?
 Is energy transported from
one point to another by a
repeating vibration?
 Is there a transport
medium?
 Is the energy transported
through the medium, with
the medium itself returning
to it’s original position? WAVE?

9. The Great Debate
Isaac Newton: Light energy is
carried as a packet of energy.
Christiaan Huygens: Light
energy is carried as a wave.
Then along came Thomas Young

10. Technically you’re both right…

12. So what is the “medium” for light?
Light does not have a physical medium.
Rather than traveling through a
solid, liquid, or gas – light is actually a
disturbance in the Universe’s Electromagnetic
Field!

13. What is the
Electromagnetic Field?
• The electromagnetic field is invisible
and can’t be “felt” the way a physical
(solid, liquid, or gas) medium can.
• The electromagnetic field extends
indefinitely (without end) throughout
space and across the universe.
• It is a combination of electric and
magnetic fields created by charged
particles.
If we can’t see it or feel it (in the
conventional sense) how do we know it’s
there?
• Aurora Borealis
• Static Electricity
• Magnetic Compasses

14. Classifying Waves

15. How are WAVES classified?
Waves can be classified by
what they move through or
by how energy moves
through them.

16. Classification of Waves
By What They Move
Through

17. There are two classifications for
waves based on what they move
through:
• Mechanical Waves
• Electromagnetic Waves

18. Mechanical Waves
Mechanical Waves: Mechanical waves are waves that can only
move through a physical medium.
 Physical Mediums are made up of matter and take the form of
solids, liquids, or gases.
Examples:
 Water Waves
 Earthquake or Seismic waves
 Sound Waves
 Rope or Slinky Waves
 Stadium Waves
Remember that all these waves require a physical transport
medium. Without matter (in a vacuum) they aren’t able to work.
 Vacuum: Refers to empty space. Space that is not filled with
matter in any form.

19. Electromagnetic Waves
Electromagnetic Waves: Electromagnetic waves are
waves that do not require a physical transport medium.
They travel along the universes electromagnetic field.
 In other words they can travel through a vacuum.
 Electromagnetic waves can also still pass through
physical mediums. They just don’t depend on them.
Examples:
 Radio Waves
 Microwaves
 Infrared Waves
 Visible Light
 Ultraviolet Rays
 X-Rays

20. Classifying Waves By
HOW Energy Moves
Through Them

21. There are three classifications
for mechanical waves based on
how energy moves through
them:
Transverse Waves
Longitudinal Waves
Surface Waves

22. Transverse Waves
Transverse Waves: Waves in in which
the the medium vibrates perpendicular
(at right angles to) the direction the
wave travels.
Examples: Waves in a Rope, Vibrating
Guitar String, Light Waves (Special
Type)

23. LONGITUDINAL WAVES
Longitudinal Waves: Waves in which the
vibration (or disturbance) is parallel to the
direction of the motion of the wave.
Examples: Sound Waves

24. Surface Waves
Surface Waves: Waves that
travel along the surface
separating two different
mediums.
- Particle motion is circular.
Examples: Water Waves

25. Real World Connection: Earthquakes
What type of waves do earthquakes produce?
Answer: All Three!

26. Real World Connection: Earthquakes
 Primary Waves: The Primary or
P Waves of an earthquake
travel the fastest and are the
first to be felt. They are
longitudinal.
 Secondary Waves: The
secondary or S waves of an
earthquake radiate out more
slowly and arrive several
seconds after the P Waves.
They are transverse.
 Rayleigh Surface Waves: These
are the last waves to arrive
and are accompanied by the
largest up and down and side
to side motion. They are
responsible for the majority of
destruction and damage. They
are Surface Waves.

27. Warm Up: Which wave is Transverse
and which is Longitudinal?
Wave A
Wave B

28. Check For Understanding
A transverse wave is transporting
energy from East to West. The
particles of the medium will
move_____.
A) East to West only
B) Both Eastward and Westward
C) North to South only
D) Both Northward and Southward

29. Check For Understanding
A wave is transporting energy from left to
right. The particles of the medium are
moving back and forth in a leftward and
rightward direction. This type of wave is
known as a ____.
A) Mechanical
B) Electromagnetic
C) Transverse
D) Longitudinal

30. Check For Understanding
You go to Comic-Con to get
your picture taken with
Batman. While waiting in line
you decide to be the cool guy
who starts a crowd wave. Is
this wave transverse or
longitudinal?

31. Check For Understanding
Why would you be far less popular if you
attempted to start a longitudinal crowd wave
instead?

32. Check For Understanding
A sound wave is a mechanical wave, not an
electromagnetic wave. This means that:
A) Particles of the medium move
perpendicular to the direction of energy
transport.
B) A sound wave transports its energy
through a vacuum.
C) A physical medium is required in order
for sound waves to transport energy.
D) All of the above.

33. Check For Understanding
A science fiction film depicts
inhabitants of one spaceship (in
outer space) hearing the sound of
a nearby spaceship as it zooms
past at high speeds. Critique the
physics of this film.

34. Check For Understanding
A transverse wave is transporting energy from East to
West. The particles of the medium will move_____.
A) East to West only
B) Both Eastward and Westward
C) North to South only
D) Both Northward and Southward
Correct Answer: D
The particles would be moving back and forth in a direction
perpendicular to energy transport. The waves are moving
westward, so the particles move northward and southward.

35. Check For Understanding
A wave is transporting energy from left to right. The particles of the
medium are moving back and forth in a leftward and rightward
direction. This type of wave is known as a ____.
A) Mechanical
B) Electromagnetic
C) Transverse
D) Longitudinal
Correct Answer: D
The particles are moving parallel to the direction that the wave is moving. This
must be a longitudinal wave.

36. Check For Understanding
You go to Comic-Con to get
your picture taken with
Batman. While waiting in line
you decide to be the cool guy
who starts a crowd wave. Is
this wave transverse or
longitudinal?
Wave Direction
Answer: Transverse

37. Check For Understanding
Why would you be far less popular if you
attempted to start a longitudinal crowd wave
instead?
Correct Answer:
Wave Direction

38. Ouch!
Ouch!
Ouch!
I hope Batman
hits you with a
Bat-A-Rang… in
the face/

39. Check For Understanding
A sound wave is a mechanical wave, not an electromagnetic
wave. This means that:
A) Particles of the medium move perpendicular to the
direction of energy transport.
B) A sound wave transports its energy through a vacuum.
C) A physical medium is required in order for sound waves to
transport energy.
D) All of the above.
Correct Answer: C
Mechanical waves require a physical medium in order to transport energy.
Sound, like any mechanical wave, cannot travel through a vacuum.

40. Check For Understanding
A science fiction film depicts inhabitants of one
spaceship (in outer space) hearing the sound of
a nearby spaceship as it zooms past at high
speeds. Critique the physics of this film.
Correct Answer:
This is an example of faulty physics in film. Sound
is a mechanical wave and could never be
transmitted through the vacuum of outer space.

41. Anatomy of a Wave

42. Crests, Troughs, and Cycles
 Cycle: Single repeating
unit of a wave. Waves are
made up of many cycles.
 Crest: The high point of a
wave cycle.
 Trough: The low point of
a wave cycle.

43. Wavelength (λ) and
Amplitude
Wavelength: The distance between any
point on a wave and the equivalent point
on the next cycle.
 Generally expressed as the distance
from crest to crest or trough to
trough.
 Basically the length (distance) of one
cycle.
Amplitude: The maximum distance the
wave rises above the rest position (or
drops below).
 In other words the height of a crest or
depth of a trough.
@ Rest

44. Period
 Period: How much time it
takes for a wave to complete
one full cycle.
 Units are always in terms of
time (seconds).
 The faster a wave moves, its
wave period becomes smaller.
 If you stood at a fixed point
(like the oil rig). You could by
measure the period of the
waves starting your watch as
a peak was passing by you and
timing how long it took for
the next peak to arrive.

45. Frequency
 Frequency is a measurement of how
often a recurring event, such as a
wave, occurs in a measured amount of
time.
 Frequency is a term you may already be
familiar with.
 How frequently do you clean your room?
 You might respond: I clean my room 1
time per week or 2 times per year (Yuck!).
 Frequency: How many cycles a wave
makes in a given period of time.
 Hertz: The unit used for frequency.
Means one wave cycle per Second.
 If a wave has a frequency of 500 Hz. How
many cycles per second are there?

46. Period vs. Frequency
Period is how
many seconds go
by in 1 cycle.
Frequency is
how many cycles
happen in 1
second.
Period and Frequency are closely related
but they are NOT the same thing!

47. Which wave has a higher frequency?
Answer: Blue
Time

48. The Relationship Between
Frequency and Wavelength
 Frequency is basically the
number of cycles in a
second.
 Wavelength is the length
(distance) of one
cycle, usually in some form
of meters.
Therefore if you combine these units you get:
Cycle
Second Cycle
Meters Meters
Second
Otherwise known as Speed

49. Speed is a Constant
The Speed of a wave depends only on
the type of wave and the medium.
 Light = 299,792,458 m/s
 Sound = 340.29 m/s
Therefore Frequency and Wavelength
must be interrelated:
 As wavelength increases, frequency
must decrease.
 As wavelength decreases, frequency
must increase.

50. But what about longitudinal waves?

51. Sound Waves are a little different…
Compression: When the medium (molecules) are forced, or
pressed, together.
Rarefaction: is just the opposite, it occurs when molecules are given
extra space and allowed to expand.

52. However for mathematical analysis it’s often easier to just
draw sound waves as “transverse” with compressions
corresponding to peaks and rarefactions to troughs.

53. Why should you care about
wave anatomy?
The anatomy of a wave tells
you how much energy the
wave is carrying!

54. Amplitude
 Amplitude tells you the how
much energy the wave is
carrying.
 Large Amplitude = High Energy
 Small Amplitude = Low Energy
 For light the amplitude of
the wave tells you how
bright the light will be.
 For sound the amplitude of
the wave tells you how loud
the sound will be.

55. Frequency / Wavelength
Remember! Frequency and wavelength have an indirect
relationship (as one goes up the other has to go down).
 Frequency also corresponds to energy.
 High Frequency (Short Wavelength) waves carry more energy.
 Low Frequency (Long Wavelength) wave carry less energy.
 For light the frequency / wavelength of the wave tells you
what color the light will be.
 High Frequency (Short Waves) = Violet Light (For Visible Light)
 Low Frequency (Long Waves) = Red Light (For Visible Light)
 For sound the frequency / wavelength of the wave tells you
what pitch the sound will have.
 High Frequency (Short Waves) = High Notes
 Low Frequency (Long Waves) = Low Notes

56. High Frequency
and
Short Wavelengths
Low Frequency
and
Long Wavelengths

57. How to Remember the Energy
Difference Between Radio Waves
and Gamma Rays…
VS.