P2 - Energy Transfers by heating (PAPER 1) Flashcards
What does a material’s thermal conductivity show
how well it conducts heat
What type of material has a low thermal conductivity
thermal insulators
What are 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 thermal heat loss from a building
thickness of walls and roof, thermal conductivity of walls and roof, temperature difference between the two sides of wall and roof
What is Specific Heat Capacity
the amount of energy required to raise the temperature of 1kg of a material by 1*C
What is infrared radiation
a type of electromagnetic radiation
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, and does not reflect or transmit any radiation
What human activities increase the levels of greenhouse gases released
deforestation, burning fossil fuels, livestock farming etc.
Why do greenhouse gases increase the Earth’s temperature
Earth’s surface absorbs and re-emits radiation from the Sun, which greenhouse gases then absorb - they re-emit this radiation back towards Earth’s surface
