Waves

1. Includes:1. Water2. Sound3. Light4. Heat5. Earthquakes

Waves

2. Wave = disturbance that transfers energy from place to place

3. Waves & Energy

1. What carries waves?2. How do waves transfer energy?3. What causes waves?

3.1 What carries waves?• What do sound waves travel through?• What do water waves travel through?

AIR

WATER

MEDIUM

1. Medium = substance or material that carries the wave (what the wave travels through)

2. Mechanical wave = requires a medium to transfer energy

3. Electromagnetic wave = doesn’t require a medium to travel through

3.2 How do waves transfer energy?

Particles in motion

Ex: Stadium

3.3 What causes waves?

1. Disturbances from energy(wave in water, sound, movement)

Question #1

TRUE or FALSE?In order for Shane to hear Sally, air molecules

must move from the lips of Sally to the ears of John

FALSE – particles only temporarily move

Question #2

• Every minute, ocean waves continue to splash onto the shore.

• In tables, explain why the beach is not completely submerged with water and why the middle of the ocean has not yet been depleted of its water supply?

Answer

• Ocean waves don’t transfer water, they transfer ENERGY

• The particles just oscillate back and forth

4. Types of waves

• Waves move through mediums in different ways

OR

4.1 Transverse Waves• Transverse waves = move the medium at right

angles to the direction of the wave• OR• = move medium perpendicular to the

direction of the wave• EX:

(4.1 Transverse Waves Continued)

• Examples: heat waves, light waves, seismic (earthquake waves)

4.2 Longitudinal Waves

• Longitudinal waves = move the medium parallel to the direction of the wave

• Ex:

(4.2 Longitudinal Waves Continued)

• Examples: sound, seismic waves (earthquake)

• Particle motion• Wave animation

Question #3: Which type of wave is each? Transverse or Longitudinal?

Properties of Waves

Transverse Wave

wavelength Direction of wave

Resting pointamplitude

Key words for Transverse

• Resting point• Amplitude• wavelength

Longitudinal Waves

Key words for Longitudinal

• wavelength

Electromagnetic vs. Mechanical• Electromagnetic waves

do not need a medium to transfer the energy

• Ex: Light, heat waves

• Mechanical waves need particles (mediums) to transfer the energy

• Ex: Sound, Earthquake waves

• http://www.google.com/imgres?hl=en&sa=X&tbo=d&biw=1278&bih=593&tbm=isch&tbnid=B87U9RZ_AfXFsM:&imgrefurl=http://missionscience.nasa.gov/ems/02_anatomy.html&docid=ERyyLXsEaXywSM&imgurl=http://missionscience.nasa.gov/images/ems/emsAnatomy_mainContent_wave-movement.png&w=600&h=158&ei=8mmVUK-FBeizigKSj4GgAg&zoom=1&iact=hc&vpx=76&vpy=288&dur=472&hovh=82&hovw=312&tx=234&ty=46&sig=110393057380908509629&page=1&tbnh=65&tbnw=248&start=0&ndsp=17&ved=1t:429,r:6,s:0,i:93

• http://www.kirksville.k12.mo.us/khs/teacher_web/alternative/transverse_wave.jpg• http://hyperphysics.phy-astr.gsu.edu/hbase/sound/imgsou/lwav2.gif• http://static.ddmcdn.com/gif/noise-canceling-headphone-8.jpg• http://scienceprep.org/images/waves.jpg• http://www.astarmathsandphysics.com/o_level_physics_notes/o_level_physics_notes_longitudinal_and_transverse_waves_html_m3d0975ac.gif• http://science-class.net/Notes/Images_8th_Notes/Longitudinal-Wave.gif