6 • Heat Transfer

Define Conduction

The transfer of heat through a medium without any overall movement of that medium

Name a medium in which conduction would occur

Metal

Label This Diagram

To Compare the rates of Conduction through different substances

a - thumb tacks

b - different metals

c - boiling water

Define Convection

The transfer of heat by the circulation of a fluid

Name 2 mediums in which convection would occur

• Liquids

• Gases

Label This Diagram

Convection in a gas

a - string

b - material cut out into a spiral

c - spinning

d - heat source

Label This Diagram

Convection in a liquid

a - heat source

b - purple dye crystal

c - convection current

d - beaker

e - water

Define Radiation

The transfer of heat by electromagnetic waves

Name a medium in which radiation would occur

Vacuum - can travel in no medium

Label This Diagram

Heat Loss From a Building

a - 30%

b - 30%

c - 20%

d - 20%

Define U-Value

The heat energy crossing 1m2 per second for every 1K difference between two sides

Differentiate between the types of U-Value

• High U Value - poor insulation

• Low U Value - good insulation

Define Solar Constant

The amount of solar energy hitting 1m2 of the earths atmosphere every second

Label This Diagram

The Thermos Flask

a - walls

b - vacuum