1. Physical Science
Chapter 15 Waves
Section 1

2. Physical Science Chapter 15 Waves
A disturbance that transits (carries) ENERGY through matter or space.

3. Physical Science Chapter 15 Waves
Most waves travel
through a medium.
A medium is some kind
of physical environment
(matter) through which
the waves travel.

4. Physical Science Chapter 15 Waves
Mechanical Waves
The types of waves
that require matter
to transmit energy
through are called
mechanical waves.

5. Physical Science Chapter 15 Waves
If a wave moves through MATTER, the matter moves back and forth or up and down, but the matter does NOT move with the energy.

6. Physical Science Chapter 15 Waves
Electromagnetic Waves
Waves caused by a disturbance in electric and magnetic fields.
Do NOT require matter (a medium) to transmit energy through.
Also referred to as “light waves”.

7. Physical Science Chapter 15 Waves
Electromagnetic Waves
As you will learn later, moving electric charges create
magnetic fields
and moving
create electric
current.

8. Physical Science Chapter 15 Waves
Mini-Quiz #1
1). What is the definition of a
wave?
2). What is the primary difference
between mechanical waves
and electromagnetic waves?

9. Physical Science Chapter 15 Waves
Team Mini-Quiz #1
1). What is the definition of a wave?
A disturbance that transits ENERGY through matter or space.
2). What is the primary difference between
mechanical waves and electromagnetic waves?
Mechanical waves need a medium to travel through.

10. Physical Science Chapter 15 Waves
Team Mini-Quiz #1
3). What are the SEVEN types of EMR?
Radio waves, microwaves,
infrared, visible light,
ultraviolet, X-rays, gamma rays.
4). What are the seven colors of visible light?
red, orange, yellow, green, blue, indigo and violet.

11. Physical Science Chapter 15 Waves
A disturbance that transfers ENERGY through matter or space.
But WHAT causes the “disturbance” that creates the wave?

12. Physical Science Chapter 15 Waves
Vibrations
Vibrate: to move
back and forth
(usually rapidly
and with a
steady
rhythm).

13. Physical Science Chapter 15 Waves
Vibrations
Involve transfers of energy
To create
vibrations in
a slinky, you
have to move it
sideways or up-and-down
You transfer energy to the slinky

14. Physical Science Chapter 15 Waves
Vibrations: Mechanical Waves
Mechanical waves are created by a vibrating (moving) object.

15. Physical Science Chapter 15 Waves
Vibrations: Electromagnetic Waves
Electromagnetic waves are created by vibrating charged particles.

16. Physical Science Chapter 15 Waves
Transverse Wave
A type of wave that causes particles in the medium to move perpendicular (up-and-down) to the direction of the wave (energy movement)

17. Physical Science Chapter 15 Waves
Transverse Wave
Crest-
highest
point
Trough-
lowest

18. Physical Science Chapter 15 Waves
Transverse Wave
Wavelength-
a complete
cycle
Amplitude-
distance up
to a crest or
down to
a trough

19. Physical Science Chapter 15 Waves
Longitudinal (Compressional) Wave
A type of wave that causes particles in the medium to move in the same direction (parallel to the movement or back-and-forth) as the direction of the wave (energy movement).

20. Physical Science Chapter 15 Waves
Longitudinal (Compressional) Wave
Compression- region where the medium is
pushed together
Rarefaction-
region where the
medium is spread
out.

21. Physical Science Chapter 15 Waves
Longitudinal (Compressional) Wave
Wavelength-distance from
compression to compression.

22. Physical Science Chapter 15 Waves
Surface Waves
Combines the motions of transverse waves
and longitudinal
waves, so the
medium moves
in a circular
motion.

23. Physical Science Chapter 15 Waves
Surface Waves
Surface waves occur at the boundary between two different mediums.
Water and air (ocean waves)
Ground and air (earthquake waves)

24. Physical Science Chapter 15 Waves
Surface Waves
Water waves
Medium particles
move in a circle; they do
not move with the energy
(Fig. 9p. 513)

25. Physical Science Chapter 15 Waves
Surface Waves
Water waves
The circles get
smaller as the
water gets
deeper.

26. Physical Science Chapter 15 Waves
Seismic Waves
Waves traveling through the Earth
(or other body) caused by
earthquakes, explosions, etc.
There are two types, P and S types.

27. Physical Science Chapter 15 Waves
Seismic Waves
(Body Waves)
P (primary waves)
are longitudinal
S (secondary)
waves are
transverse.

28. Seismic Waves Two main types of seismic waves:
Body waves travel through
Earth’s interior
Primary waves (P-waves)
Secondary waves (S-waves)
Surface waves travel on
Earth’s surface
Rayleigh waves
Love waves
CPS5e, Section 21.1
Figure 21.3

29. Physical Science Chapter 15 Waves
Surface Waves
Tsunamis-
Giant surface waves

30. 2). Draw a transverse wave; label the two parts of the wave?
Mini-Quiz #2
1). What causes most waves?
2). Draw a transverse wave; label the two parts of the wave?
3).Draw a longitudinal wave; label the two parts of the wave.
4). What is different about the direction of movement of the medium in transverse and longitudinal waves?
5).Describe the motion of a surface wave & give an example.

31. Physical Science Chapter 15 Waves
Team Mini-Quiz #2
1). What causes most waves?
Vibrations
2). Draw a
transverse wave
crests and
troughs

32. Physical Science Chapter 15 Waves
Team Mini-Quiz #2
3).Draw a longitudinal wave
compressions
rarefactions

33. Physical Science Chapter 15 Waves
Team Mini-Quiz #2
4). What is different about the medium movement
in transverse and longitudinal waves?
In transverse waves the medium moves at 90 degrees to the direction of wave movement (“up-and-down”). In compressional waves the medium moves in the same plane as the direction of wave movement (‘back-and-forth.”)

34. Physical Science Chapter 15 Waves
Team Mini-Quiz #2
5).Describe the motion of a surface wave & give an
example.
The medium in surface waves moves forward and back and up and down, creating circular movement. An example is a water wave.