Physics - Conduction, Insulation

What is conduction

Conduction is the transfer of heat by particles colliding with each other.

Why are metals the best conductors ?

• Because they have a high Thermal Conductivity.

• The particles are really closely packed so the vibrations are passed on very quickly and the delocalised electrons aid in this as well.

What is thermal conductivity?

A measure of how quickly an object transfers energy by heating through conduction.

Materials with a high thermal conductivity are...
Materials with a low thermal conductivity are...

Good Conductors,

Bad conductors, good insulators

How do insulators work? (3)

Low thermal conductivity
Have pockets of air
Air is a gas, gases are very good insulators.

What is payback time?

Equation:

The payback time of an energy-saving solution is a measure of how cost-effective it is.

Payback time (Yr) \= Cost of installation(£)/ Savings per year (£/yr)

Insulation required practical:
Which will be the best at retaining heat?
What is the method? (4)
Name the materials..

1. Pour 100ml of hot water into your beakers.
2. Place the polystyrene cup and different lids of different materials onto the beaker. Using a thermometer take the temperature of the water and start your timer.
3. Every minute take a temperature reading for the next 12 minutes.
4. Draw a cooling curve of temperature against time. Draw all the curves on the same graphs.

Materials: Draw a cooling curve of temperature against time. Draw all the curves on the same graphs