MT 5 LT 2

1
MT 5 LT 2 Behavior Of Waves
2
Lets Review LT 1 Basic Properties of
Transverse Waves

• Amplitude
• Wavelength
• Frequency
• Speed

DO NOT COPY
3
Amplitude

• Amplitude is the distance from the rest to crest
  or rest to trough.
• Farther medium moves as it vibrates, larger the
  amplitude.
• Greater the amplitude, greater the amount of
  energy

DO NOT COPY
4
Wavelength

• Wave travels certain distance before it starts to
  repeat.
• Distance between 2 corresponding parts of a wave
  .
• Transverse
• measure from crest to crest or trough to trough.

DO NOT COPY
5
Properties of Longitudinal/Compressional Waves
DO NOT COPY
6
Longitudinal Wave

• The motion of the medium vibrates in the same
  direction (parallel) as the wave travels.
• Example Slinky

DO NOT COPY
7
Longitudinal Wave

• Compressions
• The parts where the coils are close together
• Rarefactions
• the parts where the coils are spread out

DO NOT COPY
8
Amplitude of a longitudinal wave.

• The amplitude of a longitudinal wave is a measure
  of how compressed or rarefied the medium becomes.

DO NOT COPY
9
Wavelength

• Distance between 2 corresponding parts of a wave.
• Longitudinal measure from one compression to the
  next.

DO NOT COPY
10
How do waves interact?

• LT 2 - Wave Behaviors

11
What happens when

• Wave Behaviors

• A wave meets a hard surface like a wall?
• A wave enters a new medium?
• A wave moves around an obstacle?
• A wave meets another wave?

12
How do waves interact?

• Wave Behaviors

13
Ways Waves Interact

• Reflection
• Refraction
• Diffraction
• Interference
• Constructive
• Destructive
• Doppler Effect
• Polarization

14
Reflectionpg 508

• What happens when a wave hits a wall or some
  other fixed object?
• To find out, tie a rope to the back of a chair.
  Gently shake the rope up and down once to send a
  single pulse along the rope as shown. Observe
  what happens when the pulse hits the chair.

15
Reflection

• Video Click Here
• Definition
• If reflection occurs at a fixed boundary, the
  reflected wave will be upside down compared to
  the original wave.
• This happens because the wave hits a fixed
  barrier and bounces off of it

16
Reflection

• Important
• In Reflection wave hits a FIXED barrier and
  cannot pass

• Real Life
• Basketball off backboard
• Related Items
• mirror
• Frequency, angle
• Fixed boundaryflipped reflection
• Sound would echo

17
Refractionpg 509

• Video Click Here
• Definition
• All waves change speed when they enter a new
  medium.
• Bending occurs when one side of the wave enters
  the new medium before the other side.

18
Refraction
Ex Pencil half in water, half in air and it
looks bent
19
Refraction

• Important
• Wave must enter NEW medium at an angle-wave
  changes speed

• Real Life
• Hard to spear a fish
• Related Items
• Wavelengths travel at different speeds in
  different substances
• medium-air vs water
• wave speed

20
Reflection v Refraction

• Reflections barrier is not moving, it is fixed
  as wave hits it
• (The wave cant pass through it)
• Refraction wave bends as it continues into a new
  medium speed also changes.

21
Diffractionpg 510

• Video Click Here
• Definition When a wave passes a barrier or moves
  through a hole in a barrier it bends and spreads
  out.

22
Diffraction

• Important
• Wavelength determines diffraction as well as gap
  size.
• Long wavelengthlong diffraction bends and
  spreads out a lot
• Short wavelengthshort diffraction slightly bends

• Real Life Connection
• Waves that travel around a log or move through a
  gap
• Related Items
• Wave speed
• Bend
• barrier

23
Interference Constructive Destructive

• Video Click Here

24
Constructive Interferencepg 511

• Definition Constructive interference occurs
  whenever two waves combine to make a wave with a
  larger amplitude.

25
Constructive Interference

• Important
• Constructive waves build on each other

• Real life Connection
• Rouge waves
• Related Items
• Amplitude increases
• Bigger wave

26
Destructive Interferencepg 511

• Definition Destructive interference when the
  amplitudes of two waves combine producing a
  smaller amplitude.

27
Destructive Interference

• Important
• Destructive waves can cancel each other

• Real life Connection
• Muffler on a car
• Related Items
• Amplitude decreases
• smaller wave

28
Doppler Effectpg 516

• Video Click Here
• Definition Change in pitch of a sound source due
  to the relative motion of the source and the
  observer.
• Observed when a police car, w/sirens blaring,
  passes you, traveling in the opposite direction,
  at a high speed.

29
Doppler Effect

• It is about pitch, NOT loudness.
• As something gets closer, it has a higher pitch
• As it passes you, the pitch gets lower

30
Doppler Effect

• Important
• Long Wavelength creates a low frequency/pitch
  after car passes you
• Small Wavelength creates a high frequency/pitch
  as car approaches you

• Real Life
• Cant hear oncoming cars
• Related Items
• Faster the object moves, the closer in front and
  farther in back the waves get

31
Polarizationpg 548-549

• Video Click Here
• Definition (ONLY with Transverse waves)
• Transverse waves can travel in all directions. If
  it is linearly polarized (made to go through a
  filter), then the transverse vibrations in the
  wave are all in the same direction.
• Light is frequently used as an example of
  polarization.

32
Polarization

• Important
• Unpolarized light vibrates in all directions
• Polarized light vibrates in one direction

• Real Life
• Polarized Sunglasses
• Related Items
• Plane-flat surface
• Light waves that travel in all directions

33
You should have.

• a. If reflection occurs at a fixed boundary, the
  reflected wave will be upside down compared to
  the original wave.
• b. Refraction occurs when a wave enters a new
  medium at an angle because one side of a wave
  front moves more slowly than the other side.
• c. The larger the wavelength is compared to the
  size of an opening or obstacle, the more a wave
  diffracts.
• d. The types of interference are constructive and
  destructive interference.

34
Take a few minutes and fill this out..
35
Polarization

• Important
• Unpolarized light vibrates in all directions.
• Polarized light has been filtered and only
  vibrates in one plane

• Real Life
• Sunglasses
• Related Items
• Plane-flat surface
• Light waves-all directions