AQA Physics Unit 1 - Heat Transfer's

This is where heat is transfered without the object moving. 

Metals are good because: 

CLOSE ATOMIC STRUCTURE

FREE ELECTRONS

        Particles Move in this transfer. Density changes. Heat = less dense because of more movement. At the top it cools, less energy, more dense and sinks. To Create a current.    HAPPENS IN FLUIDS                                                         

HEAT IS TRANSFERRED AS INFA-RED RADIATION

Electromagnetic Wave

All object's absorb and give off heat radiation.

Dark Surfaces = Absorb more, and emit more

Light Surfaces = Reflect more, and emit less. 

WE CAN SAVE HEAT (AND ENERGY) BY:

ROOF - roof insulation (20% reduction, expensive)

DOOR AND WINDOW - Draught Excluders (15% and Cheap, need fresh air still!)

WALLS - Wall insulation (35%, expensive)

WINDOWS - Double Glazing (10%, expensive)

FLOOR - Carpet (easy to install, expensive)

EACH OF THESE INSULATES THE HOUSE

THERMOS FLASK

These are designed to keep in heat, (OR KEEP OUT). 

It uses VACUUMS. (STOP'S CONDUCTION, can't travel through Vacuum, STOP CONVECTION, No particles)

It uses Shiny Surfaces. (DOESN'T ABSORB HEAT IN FLASK, REFLECT'S BACK INWARDS).