The document provides an overview of waves, emphasizing their classification into mechanical and electromagnetic types. It explains how mechanical waves require a medium for energy transfer and details the characteristics of wave motion, including amplitude, wavelength, and frequency. Additionally, it discusses the behavior of different wave types like longitudinal and transverse waves, along with their respective examples.

1. WAVES
WAVES

2. WAVES
WAVES
 Carries energy from one place to another
Carries energy from one place to another
 Classified by
Classified by what
what they move through
they move through
1.
1. Mechanical Waves
Mechanical Waves
the energy is transferred by vibrations of medium
the energy is transferred by vibrations of medium
(medium = matter)
(medium = matter)
ex/ ocean waves move through water
ex/ ocean waves move through water
2.
2. Electromagnetic waves (EM Waves)
Electromagnetic waves (EM Waves)
the energy moves through disturbances in the
the energy moves through disturbances in the
electromagnetic field.
electromagnetic field.
a disturbance that transfers energy

3. WAVE STRUCTURE
WAVE STRUCTURE
CREST (peak)
AMPLITUDE
resting to max peak
WAVELENGTH
TROUGH

4. MECHANICAL WAVES
MECHANICAL WAVES
travel through & gradually
lose energy to that
medium
 Examples:
Examples:

water, sound, rope, &
water, sound, rope, &
spring waves
spring waves
 Mechanical Media:
Mechanical Media:

water, air, rope, spring
water, air, rope, spring
require a medium (the material through which the
disturbance is moving) to transmit energy
Making a pulse

5. MECHANICAL WAVES
MECHANICAL WAVES
Classified by how medium vibrates
Pulse = direction of energy transfer
Vibration = direction of vibration of medium
relative to pulse
3 types: Longitudinal, transverse, surface

6. MECHANICAL WAVES
MECHANICAL WAVES
Classified by how medium vibrates

7. TRANVERSE WAVES
TRANVERSE WAVES
 Sideways or up & down
Sideways or up & down
 Examples:
Examples:

S-type earthquake waves
S-type earthquake waves

Electromagnetic (EM) or light
Electromagnetic (EM) or light
waves
waves
Vibration is perpendicular to the direction of
the motion of the wave

8. LONGITUDINAL WAVES
LONGITUDINAL WAVES
 Back and forth (compression & rarefraction)
Back and forth (compression & rarefraction)
 Also called compression or pressure wave
Also called compression or pressure wave
 Examples:
Examples:

P-type earthquake waves
P-type earthquake waves

Sound waves
Sound waves
Vibration is parallel to the
direction of the motion of the wave
Rarefraction (expansion)
Compression

9. CHARACTERISTICS OF WAVES
CHARACTERISTICS OF WAVES
Waves are described according
Waves are described according
to their
to their
 Amplitude
Amplitude
measures DISPLACEMENT
measures DISPLACEMENT
size of the disturbance
size of the disturbance
 Wavelength
Wavelength 

distance of a “repeating unit”
distance of a “repeating unit”
Also called a cycle
Also called a cycle
 Velocity
Velocity v
v
speed = how fast wave travels
speed = how fast wave travels

10. AMPLITUDE
AMPLITUDE

Distance between “rest & crest” or “rest & trough”
Distance between “rest & crest” or “rest & trough”

Gives indication of “power”
Gives indication of “power”
or “strength” of wave
or “strength” of wave
(magnitude of earthquake =
(magnitude of earthquake =
Richter scale)
Richter scale)

Does not affect
Does not affect
velocity of wave
velocity of wave

Determines loudness (sound) or brightness (EM wave)
Determines loudness (sound) or brightness (EM wave)

11. WAVELENGTH
WAVELENGTH 

 Distance between any two
Distance between any two
repeating points on a wave
repeating points on a wave
crest-crest,
crest-crest,
trough-trough,
trough-trough,
expansion-expansion,
expansion-expansion,
compression-compression
compression-compression
 Determines what colors
Determines what colors
we see; what notes we hear (pitch)
we see; what notes we hear (pitch)
 Shorter wavelengths have more
Shorter wavelengths have more
cycles per minute because they
cycles per minute because they
aren’t as long
aren’t as long

12. VELOCITY
VELOCITY v
v
 the rate at which the
the rate at which the
energy travels
energy travels;
;
speed & direction
speed & direction
 Depends on medium
Depends on medium

Mechanical waves travel
Mechanical waves travel
faster through dense
faster through dense
mediums
mediums

EM Waves are faster
EM Waves are faster
through less dense
through less dense
mediums
mediums

13. Frequency
Frequency ƒ
ƒ
 measured in
measured in
wavelengths/second or
wavelengths/second or
cycles/second
cycles/second
Hertz
Hertz (Hz) = number of
(Hz) = number of
wavelengths in 1 second
wavelengths in 1 second
 Frequency is related to
Frequency is related to
velocity:
velocity: v
v =
= ƒ
ƒ 

 How often
How often
number of wavelengths that pass any point per second
number of wavelengths that pass any point per second

14. PERIOD T
PERIOD T
 How long
How long
Amount of time for one wavelength to pass a point
Amount of time for one wavelength to pass a point
 Related inversely to frequency
Related inversely to frequency
1
1 =
= 1
1
T
T f
f
Period
Period =
= 1
1
Frequency
Frequency