Physics paper 1 : waves

• What do waves transfer?

  energy not matter
• What is Amplitude?

  The maximum displacement of a point on the wave from its rest position.
• What is the wavelength ?

  The distance from one point on a wave to the same point on the next wave.
• What is frequency?

  The number of complete waves passing a certain point.
• What type of waves have perpendicular vibrations?

  Transverse waves
• What type of waves have parallel vibrations?

  Longitudinal waves
• Longitudinal waves have what?

  Compressions and rarefactions
• An example of a Transverse wave

  Lights, water ripples
• An example of a longitudinal wave

  sound wave
• How to use the measure the speed of sound?

  Oscilloscope
• The method of speed of sound

  1)connect two microphones to an oscilloscope and signal generator to a speaker

  2)start with both microphones next to the speaker, and slowly move one microphone away , stop when they line up

  3)this means they are one wavelength apart, now use the equation
• How to measure the speed of water?

  Ripple tank
• Method for ripple tank?

  add a signal generator to ripple tank and turn it on

  2) find the frequency = counting the number of ripples in 10s and divide by 10,

  30 add a lamp to create shadows of ripples, using a metre ruler count the distance
• What's a refraction?

  when a wave crosses a boundary between two materials, it can change direction.
• When are waves only refraction?

  if they meet at a boundary
• What type of waves are electromagnetic waves?

  Transverse
• Do electromagnetic waves travel at the same or differnt speed through air/vacuum?

  same
• What do electromagnetic waves transfer?

  they transfer energy from a source to an absorber
• What's the EM wave spectrum?

  radio waves

  microwaves

  infrared

  visible light

  ultraviolet

  x-rays

  gamma rays
• The beginning of the spectrum has..

  long wavelength, low frequency
• The end of the spectrum has..

  short wavelength and high frequency
• What are radio waves used for?

  Communication, eg TV and radio
• What are microwaves used for?

  Satellites and cooking
• What are infrared used for?

  Cook and heat things, eg infrared cameras and electric heaters
• What are visible light used for?

  send data, eg Fibre optic
• What are ultra violet used for?

  Suntan and uv light
• What are x-rays and gamma rays used for?

  medicine
• Why are gamma rays dangerous?

  They can knock off electrons off atoms, this destroys cells or mutate genes, than then cause cancer.
• Is the angle of refraction less or more than the angle of incidence

  less
• Where do gamma rays ordinate from?

  the changes in the nuclei of the atom