Thermal Physics Flashcards
Key features of Solids
- molecules are close together
- molecules vibrate in fixed positions
- regular arrangement
- temp increases > molecules vibrate further and faster making solid expand
Key features liquids
- molecules are slightly further apart than in solids
- molecules are still close enough to keep a definite volume
- random movement
- temperature increase > liquid expands
Key features Gases
- molecules are much further apart than in solids and liquids
- molecules move much faster than in solids and liquids
- no definite volume
- constant collisions between molecules against walls
- higher temp>higher speed>the larger the volume
Kinetic energy
1/2 mv2
Constant (k)
Pressure x volume
Constant: P1x V1 = P2 x V2
Thermal capacity
Amount of thermal energy needed to increase temp by 1*C
Specific heat capacity (meaning)
Thermal energy needed per Kg to increase the temperature of a material by 1*C
Specific heat capacity (equation) J/kg*C
Thermal energy/ mass x change in temp
Thermal energy
Power x temp
Specific latent heat
Amount of energy needed to change the state of 1kg of a substance
Energy
Mass x specific latent heat
Thermal processes
Conduction
Convection
Radiation
Conduction (solids)
For conduction we need particles> where do we find particles? SOLIDS
When the atoms start vibrating, more and more pass through thermal energy by collisions
(Metals are good thermal conductors)
Convection
Convection does no happen in solids. It doesn’t happen in fluids, liquids and gases.
When a fluid heats up:
-particles move faster and fluid expands, taking up more space
-density decreases
Radiation
The transfer of infrared radiation
