P1 Flashcards
Convection
the transfer of heat in liquids and gases
Why does convection only occur in liquids and gases?
because the particles have to be free to move in order to rise and fall for convection to occur
How is heat transferred by convection?
particles are heated and gain energy which caused them to move faster and spread out so the gas/liquid becomes less dense and rises
Conduction
the transfer of heat through solids
What are conductors?
materials which transfer energy well
What are insulators?
materials that don’t transfer energy well
How is heat transferred by conduction?
particles are heated and gain energy which caused them to vibrate and collide with the other particles, transferring the heat energy
Why are metals good conductors?
metals contain free moving electrons which can transfer energy to different parts of the metal by colliding with ions and transferring the energy
infrared
radiation emitted and absorbed by all objects, the hotter an object the more radiation it gives out
What surfaces are good absorbers?
black, dark, matt
What surfaces are poor absorbers/ emitters of infrared?
light, shiny
What surfaces are good reflectors of infrared?
light, shiny
How does surface area affect infrared emission?
the larger the surface area, the more infrared an object emits
