energy transfers by heating Flashcards
what is the thermal conductivity of a metal
tells us how fast energy is transmitted through the material by thermal conduction
what factors affect the rate of heat loss in buildings
thickness of walls and roof
thermal conductivity of the walls and roof
if the thermal conductivity is lower what does this mean
the rate of heat loss is lower
how can thermal conductivity be reduced in buildings
thermal insulators
what is a thermal insulator and what does this mean regarding rate of energy transfer
a material that has low thermal conductivity so the rate of energy transfer through the insulator is low
what does energy transfer per second through a material depend on (3 things)
the materials thermal conductivity
the temperature difference between the two sides of the material
the thickness of the material
what is a materials specific heat capacity
the amount of energy required to change 1 kg of a substances temp by 1 degrees
what does the temp change of a substance depend on when its heated or cooled (3 things)
the mass of the substance
the type of material
how much energy is transferred to it
what is infrared radiation
a type of wave on the EM spectrum that all objects absorb and emit
how does temp related to the emission of infrared radiation
higher the temp of an object the higher the emission of infrared radiation
how does the absorption of infrared radiation related to its emission
if an object is a good absorber it is also a good emitter
if a object has a constant temp what is the relationship between the emission and absorption of infrared radiation
radiation emitted =radiation absorbed
why does an objects temp increase
it absorbs infrared radiation at a higher rate than the rate it emits it
how does the absorption and emission of IR radiation relate to earths temperature
greenhouse gases absorb the IR radiation emitted from the earth and it gets re emitted back towards earth therefore its an endless cycle and the IR radiation is trapped in the atmosphere therefore the earths temp is increasing
what human activities increase the amount of green house gas emissions
burning fossil fuels, deforestation, livestock farming
