Waves, Sound, and Light MENU

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Waves, Sound, and Light MENU
Mechanical Waves
Electromagnetic Waves
Light
Wave Properties
Color
Sound
Transparent, Translucent, Opaque
Speed of Sound
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Power Point
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Waves

• 2 types of waves
• Mechanical
• Use matter to transfer energy through a medium
• Electromagnetic
• Do not need matter to transfer energy

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Mechanical Waves

• Waves that REQUIRE a medium for the energy to
  travelExamples water waves, sound waves,
  energy moving through a slinky. What else?

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Mechanical Waves

• Use matter (Medium) to transfer energy.
• The energy is transferred from particle to
  particle.
• SOUND IS A MECHANICLE WAVE

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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.

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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

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Waves, Sound, and Light MENU
Mechanical Waves
Electromagnetic Waves
Light
Wave Properties
Color
Sound
Transparent, Translucent, Opaque
Speed of Sound
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Power Point
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Wave Properties

• Amplitude
• Wavelength
• Frequency
• Human perception of amplitude loudness
• Human perception of frequency pitch

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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

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Transverse Wave Examples
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Transverse Waves (cont.)

• Frequency and Pitch
• As frequency increases pitch gets higher
• As frequency decreases pitch gets lower

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Transverse Waves (cont.)

• Frequency and Wavelength
• As frequency increases wavelength decreases
• As frequency decreases wavelength increases

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Compressional Waves

• Medium travels slightly back and forth in the
  same direction as the energy is moving

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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
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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

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Electromagnetic Waves

• These waves do not need matter to travel
• Difference between the different waves is
  wavelength
• EM spectrum illustrates the differences

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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

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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
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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

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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

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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!!!!

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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.

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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
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Speed of Sound

• The speed of sound is different depending on the
  medium it travels through

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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

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Speed of Sound

• Sound travels better through high-density
  materials
• The closer the molecules are together, the faster
  they can collide and transfer energy

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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
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Light

• Properties of Light

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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

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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

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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)

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How do you see the things around you?
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Without light, there is no sight!
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Light REFLECTS off of objects.
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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.

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Waves, Sound, and Light MENU
Mechanical Waves
Electromagnetic Waves
Light
Wave Properties
Color
Sound
Transparent, Translucent, Opaque
Speed of Sound
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Power Point
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Transparent, Translucent, Opaque
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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

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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
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Color
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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.

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Light Color Mixing

• The primary colors of light are RED, BLUE and
  GREEN

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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.

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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