p1 - heat radiation, conduction, convection, condensation, evaporation and rate of heat transfer
- Created by: maddy
- Created on: 18-03-14 17:54
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- 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.
- Dark matt surfaces absorb infrared radiation much better than light shiny surfaces
- All objects are continually emitting and absorbing infrared radiation
- Radiation depends on surface colour and texture
- Infrared Radiation is the emission of electromagnetic waves
- 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
- Conduction of heat mainly happens in SOLIDS
- 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
- 1) When a gas cools the particles in the gas slow down and LOSE KINETIC ENERGY
- 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
- Evaporation is when particles escape a liquid
- Condensation is when gas turns to liquid
- 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
- The bigger the surface area the more infrared waves that can be emitted or absorbed by the surface
- Heat energy is radiated from the surface of an object
- Condensation and Evaporation
- Radiation
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