Waves

• What is a mechanical wave?

  Disturbances that travel through matter
• How do electromagnetic waves differ from mechanical waves?

  Electromagnetic waves do not require matter
• What is a transverse wave?

  Waves with vibrations at right angles to travel
• What is a longitudinal wave?

  Waves with vibrations parallel to the direction of travel
• What is amplitude in wave terminology?

  Maximum displacement from equilibrium position
• How is wavelength defined?

  Length of one wave measured in metres
• What does frequency measure in waves?

  Number of waves passing a point in one second
• What does the law of reflection state?

  Angle of incidence equals angle of reflection
• What happens to light when it moves from less dense to more dense mediums?

  Angle of refraction is less than angle of incidence
• What is ultrasound?

  Sound waves above 20,000 Hz frequency
• What is specular reflection?

  Reflection of parallel rays in the same direction
• What is diffuse reflection?

  Reflection of parallel rays in multiple directions
• What is the equation for wave speed?

  Wave Speed = wavelength x frequency
• How do you calculate frequency from the period of a wave?

  Frequency = 1 / period of the wave
• What are the steps to draw ray diagrams for refraction?

  1. Draw a lens (concave, convex, etc.)
  2. Draw an object on one side of the lens.
  3. Draw at least two rays from the object.
  4. Draw a ray parallel to the principal axis to the lens.
  5. Draw a ray through the center of the lens.
  6. Locate and mark the image of the object.
• What is a perfect black body in terms of radiation?

  • Absorbs all radiation
  • Acts as a perfect emitter