L7 - convection, IR and black body radiation Flashcards
(3 cards)
1
Q
cavity wall and insulation help to reduce the rate of thermal energy transfer, how?
A
it is made of two brick walls with insulation between them which traps air. both of these have low thermal conductivity so reduces rate of thermal energy by conduction.
2
Q
why us warm air less dense than cold air?
A
air particles are more spread out. less particles occupy the same value, air particles rise.
3
Q
define ‘density’.
A
number of particles occupy a specific volume.
