Waves

• Absorption is light hitting an object and getting absorbed by it.
• Transmission is when light is given off through a medium
• Refraction is the bending of light as it passes from one medium to another as the speed changed
• Reflection when light bounces of a reflective surface(mirror)
• All waves transfer energy and information without transferring matter
• what is evidence that shows when a sound or water wave travels it is the wave moving and not the air or water?

  A ball is placed on the surface of a pond and ripples move across it, the ball will move up and down but not in the direction of the ripple

  
  

  A sound wave moves through the air the energy is vibrating the air molecules but the air is not moving the sound wave is.
• What is Frequency?

  number of waves passing a point each second in hertz
• What is Wavelength?

  distance from a point on one wave to a point in the same position on the next wave in metres
• What is Amplitude?

  distance from the middle to the top or bottom of a wave (the greater the amplitude the louder the sound)
• What is a Period?

  length of time it takes one wave to pass a given point
• What is wave velocity?

  speed of the wave in the direction it is traveling (waves travel at different speeds in different material)
• What is a wavefront?

  A wavefront is a surface that represents points in a wave that are in the same phase.

  
• What is the difference between transverse and longitudinal waves?

  Transverse waves oscillate perpendicular to the direction of wave, while longitudinal waves oscillate parallel to the direction of wave.
• Longitudinal waves

  the oscillations are parallel to the direction of the wave and direction it is travelling. Sound waves are longitudinal as the wave is moving backwards and forwards as the wave passes.

  A) X
• Transverse Waves


  the oscillations of a transverse waves are perpendicular (90 degrees). Waves on the surface of water are transverse, particles in the water move up and down as a wave passes

  
• What waves are transverse and which are longitudinal?

  Transverse: Light(all EM waves), water waves, seismic waves Longitudinal: Sound waves, seismic waves(earthquake waves)
• wave speed (m/s) = frequency (Hz) × wavelength (m)
• 
  

  v = f × λ

  velocity=frequency x wavelength
• wave speed (m/s) = distance (m) ÷ time (s)
• v = d / t

  wave speed = distance ÷ time
• speed of sound= measure the time it takes for a sound to travel a certain distance
• Waves change speed when they pass between two different mediums, such as light waves refracting when they pass from air to glass.
• Do sound waves need a medium to travel?

  Yes
• Do light waves need a medium to travel through?

  No