Physics paper 2

• Where do waves transfer energy?

  In the direction there travelling
• What's the amplitude of a wave?

  The maximum displacement of a point in the wave
• What is the wavelength?


  Distance between the same point jf 2 adjacent waves
• What's frequency?


  The number of complete waves passing a certain point oer secjbd and is measured in hertz
• What do transverse waves have?

  Sideways vibrations
• What do longitudinal waves have?

  Parallel vibrations
• What's an example of transverse waves?

  Electromagnetic waves
• What's an example of a longitudinal wave?

  Sound waves
• How do you measure the speed of water ripples using a ripple tank?

  Get a signal generator attached to the dipper of a ripple tank and dim the lights and turn on the lamp. Measure the distance between the shadow lines.
• What can waves be?

  Absorbed,transmitted or reflected
• What are waves absorbed by?

  The second material. It transfers energy to the materials energy stores
• Where are waves transmitted?

  Through the 2nd material. The wave carries kn travelling through the new material which leads to refraction
• How are waves reflected?

  The incoming Ray is neither absorbed or transmitted but is sent back away from the second material
• What's the frequency of waves lowest to highest?

  Radio,micro,infrared,visible light,ultra violet,x-rays,gamma
• What's refraction?


  Waves changing direction at a boundary
• What happens when a wave crosses a boundary between 2 materials?

  It changes speed
• When does refraction happen?

  When a wave hits the boundary at an angle and changes direction
• Where does the wave bend if it slows down?

  Towards the normal
• Where does the wave bend if it speeds up?

  Away from the normal
• How does eefaction depend on?

  How much the wave speeds up or down which usually depend on the density of the 2 materials
• What's the optical density of a material?

  A measure of how quickly light can travel through
• What's the angle of refraction?

  The angle between the refracted Ray and the normal
• What are radio waves made of.

  Oscillating charges
• What are radio waves used for?


  Communication
• How can radio waves be produces?

  Using an alternating curent in an electrical circuit
• What are microwaves used by?

  Satellites
• What happens in a microwave ovens?

  Microwaves are absorbed by water molecules in the food
• What can infrared radiation be used for?

  Increase or monitor temperature
• What do fibre optic cables use to transmit data?

  Visible light
• What are optical fibres?

  Thing glass or plastic fibres that can carry data over long distances as pulses of visible light
• What is fluorescence?


  When ultra-violet radiation is absorbed then visible light is emitted
• What do x-rays do?

  Pass easily through flesh and can kill all living cells
• Are lowly frequency waves dangerous?

  No. They don't transfer much energy so mostly pass through skft tissue without being absorbed
• Can high frequency waves be dangerous?

  Yes. As they transfer lots of energy they can cause a lot of harm
• What is radiation dose measured in?

  Sieverts