Science waves

• What do all waves transfer?

  Energy from one place to another.
• Besides energy, what else can waves transfer?

  Information.
• How do sound waves transfer information?

  Through vibrations between particles.
• How do sound waves travel?

  1. Caused by vibrating objects
  2. Objects vibrate, air particles vibrate
  3. Particles squash together (compressions) and spread out
  4. Require a medium like air to travel
  5. Cannot travel in a vacuum
• What can happen to sound waves when they interact with a surface?

  1. Reflection: Bouncing off the surface
  2. Refraction: Bending as they enter a new medium
  3. Absorption: Being absorbed by the medium
• Through which medium does sound travel the fastest?

  Solids.
• How does the speed of sound in liquids compare to gases?

  Sound travels faster in liquids than in gases.
• Does sound travel faster or slower than light?

  Sound always travels much slower than light.
• What is refraction?

  Refraction is the bending of light rays as they pass from one medium to another.
• How does light bend when going from a less dense medium to a more dense medium?

  Light bends TOWARDS the normal.
• What happens to light when it moves from a more dense medium to a less dense medium?

  Light bends AWAY from the normal.
• What is the Law of Reflection?

  Angle of incidence = Angle of reflection.
• What are the key components in the Law of Reflection?

  1. Angle of incidence: The angle at which the light ray hits the surface.
  2. Angle of reflection: The angle at which the light ray bounces off the surface.
  3. Normal: A line perpendicular to the surface.
  4. Measurement: Angles are always measured between the light ray and the normal.
  5. Ray diagram: Used to visualize the reflection.
• What distinguishes specular reflection from diffuse scattering?

  • Specular Reflection:
  • Occurs on smooth, shiny surfaces.
  • Light rays reflect at the same angle.
  • Creates a clear image.

  
  

  • Diffuse Scattering:
  • Occurs on rough, dull surfaces.
  • Light rays reflect in multiple directions.
  • Does not create a clear image.
• What is the relationship between the angles of incidence and reflection in specular reflection?

  The angles are equal.
• How would you use a ray diagram to show the Law of Reflection?

  1. Draw a straight line representing the incident ray at the angle of incidence.
  2. Draw a straight line representing the normal perpendicular to the reflecting surface.
  3. Draw a straight line representing the reflected ray at the angle of reflection.
  4. Ensure the angle of incidence and angle of reflection are equal.
• What are the key properties of light waves?

  1. Produced by luminous objects like the sun, candles, and light bulbs.
  2. Travels in a straight line.
  3. Type of wave: Transverse.
  4. Can be reflected.
  5. Do not need a medium to travel.
  6. Slowed down by particles.
• In what direction does light always travel?

  In a straight line.
• What are the main similarities and differences between light waves and water waves?

  Similarities:

  • Both are transverse waves
  • Both transfer energy
  • Both can be reflected

  
  

  Differences:

  • Water waves need a medium to travel (particles)
  • Light waves do not need a medium
  • Light waves are slowed down by particles
• What is the speed of light in a vacuum?

  300 000 000 m/s.
• How do we see things?

  Light reflects off objects and enters our eyes.
• Why does light travel fastest in a vacuum?

  Light travels faster when there are fewer particles to interfere with its passage. A vacuum has no air or particles, allowing light to reach its maximum speed.
• Do light waves need particles to travel?

  No, light waves do not need particles to travel.
• What effect do particles have on light waves?

  Particles slow down light waves.
• What are the two main parts of a transverse wave?

  • Crests: The highest points of the wave
  • Troughs: The lowest points of the wave
• What happens when an identical crest and trough meet?

  They cancel each other out.
• What causes a water wave to be reflected?

  When it hits a surface.
• What is the name of the wave formed when a crest and trough meet?

  The revision wave.