Thermal physics Flashcards
describe particle arrangement for solids
- dense structure
- strong forces of attraction in fixed, regular arrangement
- vibrate around fixed positions
describe particle arrangement for liquids
- weaker forces of attraction
- close together but move past each other ini irregular arrangement
- more energy than solids
describe particle arrangement for gases
- less dense than liquids/solids
- almost no forces of attraaction
- fre to move at high speeds in random motion
what are three forms of heat transfer?
- conduction
- convection
- radiation
what is conduction?
vibrating particles pass extra kinetic energy onto neighbouring particles
example of good conductor
metals - contain free electrons
give examples of insulators
- non-metals
- gases
how is rate of conduction affected?
- how quickly heat is transferred by conduction
- state of material
- conducting ability
- surface area
- temp difference
what is convection?
particles move from hotter region to cooler region and take heat energy with them
how is convection current formed with radiator?
hot air from radiator rises because it is less dense and displaces cooler air
- cooler air falls which is denser and flows to fill gap from rising hot air
how do you reduce convection?
use insulation which traps air so air can’t move
how is radiation different to convection and conduction?
doesn’‘t require a medium
- infra red EM wave
what type of surfaces absorb radiation more
dark
what type of surfaces reflect radiation
silvered
what is a colloid
substance microscopically dispersed evenly throughout another substance
