physics- chapter 2- energy transfered by heating

what is the best conductor of energy

metal

what are the best insulators

non-metal materials- such as fiberglass and wool

the energy transfer per second through a layer of insulating material depends on:

• the temperature difference cross the material

• the thickness of hte material

• the thermal conductiviity of the material

do all objects emit and absrob infrared radiation

yes

does higher or lower temperature of an object emit more radition

higher temperatures emdit more infrared radition in a given time

what is blackbody radition

radiation emitted by a body that absorbs all the raditaiotn iincident on it

what happens if an object absorbs more radiation than it emits

the temperature increases

what factors does the earths temperature depend on

absorption of infrared radiation from the sun, and the emission of radiation from the earths surface and atmosphere

why does co2 warm the earth

infrared radiation comes from the sun and warms the ground, the ground then emits longer wave length radiation, but the co2 molecules absorb and re-emit radiation back to the ground so it cannot leave the atmosphere

what is the specific heat capacity of a substance

the amount of energy needed to change the temperature of 1kg of the substance by 1 degrees Celsius

what is energy transferred measured in

joules

which strategies can reduce the rate of energy transfer from houses

loft insulation, cavity wall insulation, double glazed windows, aluminium foil behind radiators, external walls with thicker bricks and lower thermal conductivity