P2 Flashcards
what is thermal conductivity
the amount of energy per second an object transfers by conduction
what makes a good insulator
high thermal conductivity
thick material
how do you increase the infrared radiation being emitted from an object
increase the temperature
what is a perfect black body
an object that absorbs all the radiation that hits it so if doesn’t reflect or transmit any radiation
why do resuce teams use light coloured shiny blankets
a light, shiny outer surface emits less radiation than a dark, matt surface so the patient stays warmer
what is specific heat capacity
the energy needed to raise the temperature of 1kg of the substance by 1C
how to work out the energy change when you know the mass and the temperature change
mass x specific heat capacity ( J/Kg C) x temp change
how to work out specific heat capacity
mass x temp change
what are 5 ways to reduce energy transfer out of a house which also reduces heating bills
1) loft insulation eg fibreglass- air between fibres reduces rate of conduction
2) cavity wall insulation - reduces rate of energy transfer through outer walls of the house
3) aluminium foil between a radiator and a wall reflects radiation away from the wall
4) double glazed windows
5) thicker bricks- lower thermal conductivity
