3.5 Ways Of Transferring Thermal Energy PDF

3. 5 WAY S O F TRANSFERRING T H E R M A L E N E R GY T H E R M A L E N E R GY T R A N S F E R       METHOD 1 INTRODUCTION TO CONDUCTION When you touch a warm bottle, you feel hot. The contact between your hand and the bottle is the most direct way heat transfers –...

3. 5 WAY S O F TRANSFERRING T H E R M A L E N E R GY T H E R M A L E N E R GY T R A N S F E R       METHOD 1 INTRODUCTION TO CONDUCTION When you touch a warm bottle, you feel hot. The contact between your hand and the bottle is the most direct way heat transfers – conduction.     H OW C O N D U C T I O N O C C U R S ?   Hotter solid Colder solid (Their particles (Their particles vibrate more) vibrate less) H OW C O N D U C T I O N O C C U R S ?   The vibration gets passed on C O N D U C T I O N I N S O L I D, L I Q U I D & GA S        THERMAL CONDUCTORS    Details unimportant = electrons T H E R M A L I N S U L AT O R S    METHOD 2 INTRODUCTION TO CONVECTION Imagine you are in a cold room. You turn on the heater and after a short while, you feel the whole room becoming warm. We know air is a poor thermal conductor, so it should take a long while before you feel the heat. Thus, in this scenario, heat must be transferred via another method as well. This new method is convection.    T H E R M A L E X PA N S I O N & C O N T R AC T I O N     The opposite is true C A U S E O F E X PA N S I O N for contraction.       DENSITY CHANGE     H OW C O N V E C T I O N O C C U R S ( PA R T 1 )   Heater H OW C O N V E C T I O N O C C U R S ( PA R T 2 )   Hotter air  H OW C O N V E C T I O N O C C U R S ( PA R T 3 ) Colder air   Hotter air C O N V E C T I O N C U R R E N T ( PA R T 1 ) Colder air   Hotter air C O N V E C T I O N C U R R E N T ( PA R T 2 ) Colder air   Hotter air CONVECTION CONDITIONS      METHOD 3 I N T R O D U C T I O N T O R A D I AT I O N We feel heat coming from the Sun. The Earth is not in contact with the Sun, so no conduction occurs. Between Earth and Sun, there is (mostly) empty vacuum space, so no convection occurs. There must be a third method of heat transfer that can pass through vacuum. This is radiation.     INFRARED EMISSION  INFRARED TRANSMISSION    INFRARED ABSORPTION    M AT E R I A L S A F F E C T I N G R A D I AT I O N           A P P L I C AT I O N S C A S E 1 : F RY I N G PA N      C A S E 2 : P O S I T I O N O F H E AT E R    For the same reason, air conditioners are placed on the ceiling, not the ground.    C A S E 3 : C A R W I N D OW C OV E R S     C A S E 4 : VAC U U M F L A S K ( PA R T O N E )    C A S E 4 : VAC U U M F L A S K ( PA R T T WO )  