Waves, Sound, and Light MENU by peo25990

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									 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
                    Waves
• 2 types of waves
  – Mechanical
    • Use matter to transfer energy through a medium
  – Electromagnetic
    • Do not need matter to transfer energy
        Mechanical Waves
• Waves that REQUIRE a medium for the
  energy to travel

 Examples: water waves, sound waves,
 energy moving through a slinky. What
 else?
          Mechanical Waves
• Use matter (Medium)
  to transfer energy.
• The energy is
  transferred from
  particle to particle.
• SOUND IS A
  MECHANICLE WAVE
 There Are Two Basic Types of
      Mechanical Waves.
     Transverse Waves
• The energy traveling
  through the wave causes
  the particles to move at a
  right angle to the
  direction of the energy.
• This is what we usually
  draw when representing
  waves.
• Ripples on a pond are an
  example of these.
The Second type of Mechanical
           Wave
 Compressional Waves
• In this type the
  particles move in the
  same direction as the
  energy.
• Sound is a
  Compressional Wave
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
          Wave Properties
• Amplitude
• Wavelength
• Frequency

• Human perception of amplitude –
  loudness
• Human perception of frequency – pitch
              Transverse Waves
• Crest – very top of wave
• Trough – very bottom of wave
• Amplitude – Distance between resting position and
  crest/trough
• Wavelength – Distance from the top of one crest to the
  next crest
• Frequency – Number of wavelengths to pass by a given
  point in 1 second
   – 2.5 in picture at right
Transverse Wave Examples
    Transverse Waves (cont.)




• Frequency and Pitch
  – As frequency increases pitch gets higher
  – As frequency decreases pitch gets lower
    Transverse Waves (cont.)
• Frequency and Wavelength
  – As frequency increases wavelength decreases
  – As frequency decreases wavelength increases
Compressional Waves
         • Medium travels slightly
           back and forth in the
           same direction as the
           energy is moving
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
      Electromagnetic Waves
• Waves that DO NOT require a medium for
  the energy to travel

• Examples: Light, radio waves, x-rays,
  gamma rays, etc. All waves on the
  electromagnetic spectrum
       Electromagnetic Waves
• These waves do not
  need matter to travel
• Difference between
  the different waves is
  wavelength
• EM spectrum
  illustrates the
  differences
Electromagnetic Waves (cont.)
               • Radio – listen to your
                 favorite station
               • Microwaves – call your
                 friends
               • Infrared – night vision
               • Visible – you can see this
                 presentation
               • Ultraviolet – tanning
               • X-ray – see broken bones
               • Gamma – kill cancerous
                 cells
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
                 Sound
• Sound is a mechanical wave (requires a
  medium to travel) and a compressional
  wave (molecules colliding)

• The medium sound travels through are
  molecules when they collide
                       Sound




• Sound is produced when an object vibrates.
• When an object vibrates it exerts a force on the
  surrounding air
• Loudness of a sound is recorded in decibels
• As a sound gets louder, the amplitude of the wave
  increases
                        Sound
• The moving air mass
  carries the sound of the
  vibration to your ear.
• The air is the MEDIA that
  it travels through.
• Medium is what the wave
  travels through (ex. solid,
  liquid, gas)
• NO MEDIUM NO
  SOUND!!!!
                The Echo
• An echo is when a sound wave hits a hard
  surface and bounces back, causing you to
  hear the sound a second time

• Sonar uses echoes. It is a measure of
  how long it takes the echo to return to the
  source of the sound. Sonar can tell you
  how far an object is from you.
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
          Speed of Sound
• The speed of sound is different depending
  on the medium it travels through
Speed of Sound
       • Sound travels at
         different speeds
         through different
         medium
       • The more dense a
         material the faster
         sound travels
         – 346 m/s in warm air
         – 5,000 m/s in aluminum
         – 3,240 m/s in gold
             Speed of Sound
• Sound travels better through high-density
  materials
  – The closer the molecules are together, the faster they
    can collide and transfer energy
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
                   Light
• Properties of Light
                  Light
• EM wave that travels transversely (up and
  down motion)
• Primary colors are red, green and blue
• White light is made up of all colors
• Black is the absence of color
              Light (cont.)
• We see colors because objects reflect light
• If you see a color, that specific color is
  being reflected while the rest are being
  absorbed (taken in) by the medium
• White reflects all colors
• Black absorbs all colors
             What is Light?
• It is a transverse wave that carries energy
• It is a small part of the ElectroMagnetic
  Spectrum
• Because it is part of the electromagnetic
  spectrum, it can travel through a vacuum
  (space)
How do you see the things around
             you?
Without light, there is no sight!
Light REFLECTS off of objects.
              How we see
• When light strikes an object the light
  bounces off of the object and then into our
  eye.
• For example, the light from the this
  projector hits the screen and then is
  reflected to your eye.
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
Transparent, Translucent, Opaque
Opaque, Translucent, Transparent
• Objects that do not let light pass through
  them are opaque. Ex. Walls, your desk,
  the science book
• Objects that let light pass clearly through
  them are transparent. Ex. Windows,
  plastic wrap, eye glass lenses
• Objects that let only some light pass
  through are translucent. Ex. waxed paper,
  frosted glass
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point
Color
                COLORS
• The suns light might appear white, but it is
  a mixture of colors.
• White light is produced when you mix the
  colors of the rainbow together.
         Light Color Mixing
• The primary colors of light are RED, BLUE
  and GREEN
So why do we see different colors?

• When white light hits an object some of it
  may be absorbed by the object while the
  rest of the light is reflected. The colors we
  see are the reflected colors.
 Waves, Sound, and Light MENU
Mechanical Waves                          Electromagnetic Waves



                                                Light
  Wave Properties


                                              Color
         Sound


                                       Transparent, Translucent, Opaque
    Speed of Sound



       Click above to be taken to that section of the Power Point

								
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