P2 - Energy transfer by heating

What does a material’s thermal conductivity tell you?

How well it conducts heat

Which materials have low thermal conducticity?

Thermal insulators

Give three factors that determine the rate of thermal energy transfer through a material.

Thermal conductivity of material, temperature difference, thickness of material

What factors affect the rate of heat loss from a building?

Thickness of walls and roof, thermal conductivity of walls and roof, the temperature difference between the two sides of the wall/roof

Define specific heat capacity.

Amount of energy needed to raise the temperature of 1 kg of a material by 1°C

What is the relationship between the temperature of an object and its emission of infrared radiation?

The higher the temperature of an object, the more infrared radiation emitted in a given time

What can you tell about an object that absorbs and emits infrared radiation at the same rate?

It is at a constant temperature

Compare the amount of infrared radiation emitted and absorbed by an object that is increasing in temperature.

More infrared radiation absorbed than emitted

What is a black body?

Theoretical object that absorbs 100% of the radiation that falls on it, does not reflect or transmit any radiation, and is also the best emitter of radiation

Name three greenhouse gases.

Water vapour, carbon dioxide, methane