1. What’s the deal
with WAVE
classification?
red words= vocabulary

2. How are
WAVES
classified?

3. Waves can be classified
by WHAT they move
through or by HOW
energy moves through
them.

4. Wave Speed
 The speed of a wave depends on the
properties of the medium it is traveling
through
 In general sound waves travel the fastest
through solids then liquids then gases

Light waves travel the fastest in empty
space and slowest through solids
 Sound waves travel faster through warmer
mediums

5. The speed of waves
 The speed of a water wave is how fast the
wave spreads, NOT how fast the water
surface moves up and down or how fast
the dropped ball moves in the water.
How do we measure the wave speed?

7. Classification of
WAVES by WHAT
they
move through

8. What’s the deal with WAVE classification?
There are two classifications
for waves based on what
they move through:
• Mechanical Waves
• Electromagnetic Waves
red words= vocabulary

9. What are
mechanical
WAVES?

10. Mechanical waves are
waves that can ONLY
move through a
medium (through
matter).

11. Mechanical waves
require the particles of
the medium to vibrate
in order for energy to
be transferred.

12. What are
examples
mechanical
WAVES?

13. • water waves
• earthquake/seismic waves
• sound waves
• waves that travel down a
rope or spring
All of these examples CANNOT move
through empty space.

14. What is
EMPTY
SPACE?

15. Empty space is space in
which NO MATTER is
present. Another
name for this is a
vacuum.

16. What are
electromagneti
c WAVES?

17. Electromagnetic waves
are waves that can
travel through matter
or empty space where
matter is not present.

18. What are
examples of
electromagnetic
WAVES?

19. • radio waves
• microwaves
• infrared waves
• visible light
• ultraviolet rays
• X-rays

20. Classification of
WAVES by HOW
energy moves through
them

21. There are two classifications
for waves based on how
energy moves through them:
• Compressional/Longitudinal
Waves
• Transverse Waves

22. Seismic Waves
 Seismic waves – combination of
transverse and compressional waves
which carry energy along and through
Earth

23. What are
compressional/
longitudinal
WAVES?

24. Mechanical waves in which the
particles of matter in the
medium vibrate by pushing
together and moving apart
parallel to the direction in which
the wave travels are called
compressional/longitudinal
waves.

25. http://www.lcse.umn.edu/specs/labs/glossary_items/rarefaction_spring.html

26. The place on the wave that
is pushed together is
called the compression
and the place that is
moving apart is the
rarefaction.

27. What are examples of
compressional/
longitudinal waves?

28. • sound waves
• some waves in a spring
• some seismic waves
(earthquake waves- primary
waves, to be exact)

29. What are
transverse
WAVES?

30. Transverse Waves
 Transverse waves – matter moves in the
medium back and forth at right angles to
the direction that the wave is traveling

Light waves & water waves

31. Mechanical waves in which the
particles of matter in the
medium vibrate by moving back
and forth and perpendicular (at
right angles) to the direction
the wave travels are called
transverse waves.

32. science.hq.nasa.gov/kids/imagers/ems/waves3.html

33. The highest point of a
transverse wave is the
crest and the lowest
point is called a trough.

34. What are
examples of
transverse
waves?

35. • strings on a musical
instrument
• waves on a rope
• some waves in a spring
• some seismic waves
(earthquake waves-
secondary waves, to be exact)

36. Electromagnetic waves
are transverse waves that
can travel without a
medium through empty
space.

37. 37

38. The Parts of a Wave
 Crest – the highest points of a wave
 Trough – the lowest points of a wave

39. Wireless Communication
Radio Waves
Radio stations transmit signals by changing a radio wave’s
amplitude or frequency. What is the wave property that is
constant?
39

41. Wavelength
 Wavelength – the distance between one
point on a wave and the nearest point just
like it

42. Frequency and Period
 Frequency – the number of waves that pass a
given point each second
Ø Measured in Hertz = 1/sec
Ø Period: The amount of time it takes one
wavelength to pass a point

43. Frequency and Wavelength
 Frequency and
wavelength are
inversely related
 Long wavelength
= Low frequency

Short wavelength
= High Frequency

44. Waves of the Electromagnetic Spectrum
The Electromagnetic Spectrum
The electromagnetic spectrum can be broken up into different
categories. Use the word bank to complete the boxes in the diagram.
44

45. Four wave interactions
When a wave
encounters a
surface, four
interactions can
occur:
 reflection,
 refraction,
 dif fraction, or


47. Wave interactions
 Dif fraction usually
changes the
direction and shape
of the wave.
 When a plane wave
passes through a
small hole
dif fraction turns it
into a circular