+ transferred ONLY when there is a difference in temp
!!! flows from region of HIGHER temp TO region of LOWER temp
--> THERMAL EQUILIBRIUM:no gaining or losing of thermal energy
transferred through CONDUCTION, CONVECTION, RADIATION
ConductioN
!!! a process whereby thermal energy is transferred without flow of any material medium
the words are kind of BLUR
- different materials conduct heat at different rates
- METALS are good conductors of heat
- NON-METALS are poor conductors of heat [insulators]
IN SOLIDS
- tiny particles culd be found in ALL solids [atoms, molecules]
- metal contains many free electrons
- non-metals does not contain any of it
+ particles at hot end vibrates vigourously, colliding with other particles causing it to vibrate as well
+ when metals are heated, the free electrons in it gain KE and so it moves faster
+ those electrons as a result diffuse / spread to cooler parts
frying of egg involves conduction!! WOW! =)
IN LIQUIDS / GAS
~particles are further apart so there collisions of particles are LESS frequent
~ transfer of KE is slower
POOR conductor of heat
ConvectioN
!!! transfer of thermal energy by means of currents in ONLY fluid [liquid, gas]
- involves movement which carries thermal energy
-for SOLID, thermal energy is transferred from one particle to another through VIBRATION
+ when water is heated, it expands
+ it is less dense than surrounding water therefore it rises
+ cooler region is denser therefore it sinks
RadiatioN
!! continual emission of infrared waves from surface of ALL bodies, transmitted without medium
- can take place in vacuum
- thermal heat from infrared waves is called RADIANT HEAT
