p1 - heat radiation, conduction, convection, condensation, evaporation and rate of heat transfer

HideShow resource information
  • Created by: maddy
  • Created on: 18-03-14 17:54
View mindmap
  • Heat is transferred in 3 different ways
    • Radiation
      • Infrared Radiation is the emission of electromagnetic waves
        • Radiation depends on surface colour and texture
          • Dark matt surfaces absorb infrared radiation much better than light shiny surfaces
            • Emit much more infrared radiation
          • Light shiny surfaces reflect a lot of the infrared radiation falling on them.
        • All objects are continually emitting and absorbing infrared radiation
    • Conduction
      • Conduction of heat mainly happens in SOLIDS
        • Conduction is USUALLY faster in denser solids because the particles are closer together so will collide more often passing energy between them
      • Conduction of HEAT ENERGY is the process where VIBRATING PARTICLES pass on their EXTRA KINETIC ENERGY to NEIGHBOURING PARTICLES
    • Convection
      • Convection of heat only happens in liquids and gases.
      • Convection occurs when the more energetic particles MOVE from the HOTTER REGION yo the COOLER REGION and take the heat energy with them - SELFISH!
    • P1
      • Condensation and Evaporation
        • Condensation is when gas turns to liquid
          • 1) When a gas cools the particles in the gas slow down and LOSE KINETIC ENERGY
            • 2) If the temperature gets cold enough and the gas particles get close enough condensation can take place
        • Evaporation is when liquid turns to gas
          • Evaporation is when particles escape a liquid
            • Particles can escape a liquid at a temperature much LOWER THAN THE LIQUIDS BOILING POINT
            • The fastest particles will evaporate first as they have the most kinetic energy
              • The particles remaining have a DECREASED speed and kinetic energy
      • Rate of heat transfer
        • Heat energy is radiated from the surface of an object
          • The bigger the surface area the more infrared waves that can be emitted or absorbed by the surface
            • EG - RADIATIORS HAVE A LARGE SURFACE AREA TO MAXAMISE THE AMOUNT OF HEAT THEY TRANSFER

Comments

No comments have yet been made

Similar Physics resources:

See all Physics resources »See all Energy resources »