P1a- Energy Flashcards
What is infrared radiation?
Emission of EM waves - transfers heat
What are the 3 ways heat is transferred?
Conduction
Convection
Radiation
What surfaces are the best and worst at radiating heat?
Matt, dark surfaces are best
Shiny light surfaces worst as they reflect the radiation
How are particles held together in a solid?
Strong forces of attraction hold them together in a fixed regular arrangement
Particles don’t have much energy and vibrate around their fixed positions
Conduction of heat is…
The process where vibrating particles pass on their extra kinetic energy to neighbouring particles
Metals are food conductors because of their…
Free electrons
What is convection?
Particles with more energy move from hotter areas to colder areas
Condensation is…
When a gas turns to liquid as the gas particles cool and move together
Evaporation is when…
Particles escape from a liquid to form a gas
Particles can evaporate from a liquid at temperatures much …….. than the liquids boiling point
Lower
Particles near the surface of a liquid can escape if…(2)
The particles are travelling:
In the right direction
Fast enough to overcome attractive forces of the other particles in the liquid
Evaporation makes the remaining liquid …… as…
Cool
The average energy of the remaining particles lowers
The rate of evaporation will be higher if…(4)
Temp is higher
Density is lower
Surface area is larger
Airflow over the liquid is greater
The rate of condensation will be faster if…(4)
The temp of the gas is lower
The temp of the surface the gas touches is lower
Density is higher
Airflow is less
What is a U-Value?
They show how fast heat can transfer through a material
The higher the U value the faster the hear transfer
