Energy stores and transfer

• 8 stores of energy

  Electrical

  chemical

  kinetic

  gravitational potential

  elastic

  magnetic

  thermal

  nuclear
• Conversion of energy

  The total amount of energy in a system remains the same
• Sound is caused by …

  Vibration
• Sound is carried by …

  Longitudinal waves
• Frequency

  Is the number of waves
• Light always travels in…

  Straight lines
• What are the 3 thermal energy transfer processes

  Conduction

  convection

  radiation
• Radiation

  Is absorbed by Matte black , reflected by silver, shiny or white surfaces . All objects that are hotter than their surroundings will emit infra-red waves.
• Conduction

  Only works in solids
• Convection

  Only works in liquids
• Reflection

  When light bounces back from a surface

  
• Refraction

  An effect that occurs when waves travel into different substances

  
• Primary and secondary colours

  Primary:blue ,green and red

  secondary: magenta ,cyan and yellow

  all of the colours: white
• Energy can be transferred…

  electrically

  heating

  mechanically

  radiation
• Energy cannot be created or destroyed
• Metals are the best thermal conductors because they have free electrons to transfer the energy
• Conduction

  particles gain thermal energy and vibrate more. Vibrations are passed on to neighbouring particles by conduction many solids are good conductors because the particles are close together.
• Convection

  when a fluid is heating ,the particles gain energy and move apart. This region or fluid becomes less dense. The less dense fluid will rise,transferring the thermal energy with it. This is called convection
• The colour an object appears depends on the colours of light it reflects. All other colours are absorbed.
• if white light falls on magenta flowers ,the colours reflected would be magenta ,red and blue. If green light falls on them they will appear black because no green light has been reflected and it has been absorped.