Waves

1
Waves

• S8P4

2
Vocabulary to know

• Wave
• Medium
• Mechanical wave
• Transverse wave
• Longitudinal wave

3
??Waves??

• What is a wave?
• A wave is a repeating disturbance or movement
  that transfers energy through matter or space
• Example sound, light, water

4
Waves transfer energy not matter. The water waves
below are carrying energy. Waves can only exist
as they have energy to carry.
5
Energy and Waves
6
Energy and Waves

• Earthquakes are good examples of how energy
  travels in a wave over a long distancewith
  kinetic energy being what is transferred.
• Remember, the ground is not what is being
  transferred.it doesnt travel away from where it
  began
• Ocean waves are also good examples of how energy
  is transferred

7
Anatomy of a Seismic Wave
8
Forces and Waves

• Force is required to change the motion of an
  object.
• In order to move a rope, you have to have a force
  that moves up and a force that moves down
• Drop something in water and it will cause a
  wave
• Earthquake, a sudden release of energy that
  causes a rock to move

9
Materials and Waves

• A medium is any substance that a wave moves
  through.
• Water
• Ground
• Rope
• Solid, Liquid, Gas

10
What are mechanical waves? Mechanical waves are
waves which require a medium. A medium is a form
of matter through which the wave travels (such as
water, air, glass, etc.) Waves such as light,
x-rays, and other forms of radiation do not
require a medium therefore they are not a type of
mechanical waves.
11
How waves move

• Classifying mechanical waves
• what they move throughor the medium
• or
• How they movethere are two types

12
What are the two kinds of mechanical waves?

• 1. Transverse Waves
• In a transverse wave, the matter in the wave
  moves up and down at a right angle to the
  direction of the wave

13
Example of a transverse wave
14
What are the two kinds of mechanical waves?
2. Longitudinal Waves (Compression Waves)
In a longitudinal wave the matter in the wave
moves back and forth parallel to the direction of
the wave
15
Longitudinal Wave
16
For homework, answer the following

1. Describe how forces start waves
2. Explain how a wave can travel through a medium
   and yet the medium stays in place. (Use the word
   energy in your answer)
3. Describe two ways in which waves travel, and give
   an example of each.
4. Would water traveling in a water hose qualify as
   a wave? Why or why not?
5. If you drop a cookie in a glass of milk, you will
   see a ripple spread across the surface of the
   milk. What type of waves are these? What was
   the disturbance?

17
(No Transcript)
18
What is the Doppler Effect? The Doppler Effect is
the apparent change in frequency detected when
the sound is moving relative to the hearer.
Video-Excellent example of Doppler Effect with
car horn (26 seconds) Video-A Motorcycle does the
Doppler Effect (27 seconds)
19
Using Sound What is Acoustics? Acoustics is the
study of sound and ways to optimize the hearing
of sound inside various structures.
20
What is echolocation?
21
(No Transcript)
22
What is sonar? Sonar is a system that uses the
reflection of underwater sound waves to detect
objects. This has been used to find sunken ships
and schools of fish.