Light

• What type of wave does light travel as?

  Transverse wave
• What is the light that we detect with our eyes called?

  Visible light
• How do we see an object?

  Light is reflected off the object into our eye
• What happens for us to see a football?

  Light from the sun reflects off the ball
• What is the speed of light?

  300 million meters per second
• How long does it take for light to travel from the sun to Earth?

  Approximately eight minutes
• What are objects that emit light called?

  Luminous objects
• What are objects that do not emit light called?

  Non-luminous objects
• Give two examples of luminous objects.

  The sun and light bulbs
• How can we see non-luminous objects?

  When light reflects off them into our eyes
• Can light travel through gases?

  Yes, for example, air
• Can light travel through liquids?

  Yes, for example, water
• What do we say when light can go through objects?

  The objects transmit light
• What are objects that transmit light called?

  Transparent or translucent objects
• What is an example of a transparent object?

  Glass
• What happens to light when it hits transparent glass?

  Most light goes through, some is reflected
• What is an example of a translucent object?

  Frosted glass
• What is a characteristic of translucent objects?

  They scatter transmitted light
• What happens to light when it hits an opaque object?

  Most light is absorbed, some is reflected
• What are objects that do not transmit light called?

  Opaque objects
• What does it mean if an object is opaque?

  Light does not go through it
• What happens to light when it hits an opaque object?

  Most light is absorbed
• What are the differences between luminous, non-luminous, transparent, translucent, and opaque objects?

  • Luminous: Emit light (e.g., sun, light bulbs)
  • Non-luminous: Do not emit light (e.g., footballs, books)
  • Transparent: Transmit most light (e.g., glass)
  • Translucent: Transmit some light, scattered (e.g., frosted glass)
  • Opaque: Do not transmit light (e.g., wood)
• What are the properties of light in different mediums?

  • Travels as a transverse wave
  • Can travel through gases, liquids, and some solids
  • Speed: 300 million meters per second
  • Reflects off objects to be seen
  • Absorbed or scattered by opaque objects
• What produces waves?

  Vibrations or oscillations
• What do all waves transfer?

  Energy
• What are the two types of waves?

  Longitudinal waves and transverse waves
• What is an example of a longitudinal wave?

  Sound wave
• What are the regions called in a longitudinal wave where particles are close together?

  Compression
• What are the regions called in a longitudinal wave where particles are further apart?

  Rarefaction
• How are oscillations oriented in a longitudinal wave?

  Parallel to the direction of energy transfer
• How would you produce longitudinal waves in a slinky?

  By oscillating it back and forth
• What is the orientation of oscillations in a transverse wave?

  Perpendicular to the direction of energy transfer
• How would you produce a transverse wave on a slinky?

  By oscillating it up and down
• What basic features can be seen on a wave diagram?

  Peak and trough
• What tool can be used to view the waveform of longitudinal waves?

  Oscilloscope
• What is wavelength?

  Length of one complete wave
• How is wavelength measured?

  In meters
• What is amplitude?

  Distance between midpoint and peak
• What common mistake do people make regarding amplitude?

  Confusing it with the height of the whole wave