transfer of thermal energy

Question 1

thermal energy

Answer 1

always flows frm a region of higher temp to region of lower temp, until two regions rch the same temp
(thermal equilibrium)
whn two bodies are at thermal equilibrium, there is no net flow of thermal energy btwn them

Question 2

conduction

Answer 2

transfer of thermal energy through a medium wo any flow of the medium

Question 3

how conduction work (in all matter)

Answer 3

particles at the hot end vibrate vigorously and collide with neighbouring particles, thermal energy has been transferred wo the transfer of particles

Question 4

how conduction work (metals)

Answer 4

free electrons at the heated end absorb thermal energy and gain KE, these fast moving electrons move to the cooler regions of the metal and collide with the atoms at the cooler regions, thermal energy is transferred via the motion of free electrons

Question 5

convection

Answer 5

transfer of thermal energy by means of convection currents in a fluid due to the diff in density (only in liquids and gases)

Question 6

how convection work

Answer 6

eg. water near heat source gain heat and expands, expanded water rises as it is less dense than surrounding water , the cooler and denser water at the upper part sinks
convection current is created

Question 7

radiation

Answer 7

transfer of thermal energy in the form of electromagnetic waves such as infrared radiation without the aid of a medium

Question 8

factors that affect radiation (3)

Answer 8

colour and texture- black and dull absorb and emit infrared radiation better
surface temperature- surface temp increases, rate of emission of infrared radiation increases
surface area- emission or absorption of infrared radiation increases as surface area increases