1. Home
  2. Flashcards
  3. Preview

Energy Matters: Heat in the Home

  1. what is heat?
    heat is a form of energy that is measured in joules (J)
  2. what is temperature?
    temperature is how hot or cold an object is and is measured in degrees Celsius
  3. in what three ways can heat be transferred?
    • conduction
    • convection
    • radiation
  4. what is conduction?
    • the vibrations of hot particles are passed to their neighbours.
    • takes place in solids
  5. what is convection?
    • hot fluids are less dense than cold fluids and so they can rise while the cold fluid falls setting up a convection current.
    • takes place in liquids and gases.
  6. what is radiation?
    • energy in the form of electromagnetic rays.
    • only method through a vacuum
  7. Why does heat loss happen?
    heat always moves away from hot objects to cold objects
  8. what does the rate of heat loss depend on?
    the temperature difference between the two objects
  9. heat loss from the home be reduced by loft insulation. explain.
    reduces heat loss by conduction through the ceiling
  10. heat loss from the home be reduced by double glazing. explain.
    a vacuum between the panes of glass reduces heat loss by conduction
  11. heat loss from the home be reduced by draught excluders. explain.
    reduce heat loss by convection
  12. heat loss from the home be reduced by foil-backed plasterboard. explain.
    reduces heat loss by radiation from the walls
  13. heat loss from the home be reduced by foil-backed radiators. explain.
    reflects heat back into the room and so reduces heat loss by radiation
  14. heat loss from the home be reduced by cavity wall insulation. explain.
    a foam filling between the walls prevents heat loss due to convection
  15. heat loss from the home be reduced by carpets. explain.
    reduces heat loss by conduction through floor
  16. what is specific heat capacity?
    the quantity of heat energy required to raise the temperature of 1kg of a material by 1 oC
  17. what happens when a material changes state?
    • when a material changes state energy is either lost or gained
    • during a change of state the temperature of a material does not change
  18. what is the specific latent heat of fusion?
    the quantity of heat energy required to melt 1kg of a material
  19. what is the specific latent heat of vaporisation?
    the quantity of heat energy required to evaporate 1kg of a material
  20. what is the unit of specific latent heat?
    J/kg
  21. what applications involve a change of state?
    • refrigerators
    • picnic box cooling packs
  22. during any energy change, what cant happen?
    energy cant be created nor destroyed
Author
crobertsonx
ID
86561
Card Set
Energy Matters: Heat in the Home
Description
Energy Matters: Section 4- Heat in the Home
Updated

  1. Home
  2. Flashcards
  3. Preview