transfer of thermal energy and its effects

conduction

• the transfer of heat without the physical movements of a medium

  • solids are better conductors of heat because its particles are very closely arranged as compared to liquids and gases

    • this allows for the quick transfer of heat

• because of <insert material>→ gain/lose heat quicky/slowly→ good/poor conductor of thermal energy

convection

• the transfer of heat by the physical movement of the medium

  • fluids and gases transfer heat mainly by convection

• heat gain through convection

  • gain heat→expand→density decreases→rises→colder sinks due to higher density→gains heat and expands→creates convection current

• heat loss through convection

  • lose heat→increases in density→sinks→hotter rises due to the lower density→loses heat and increases in density→creation of convection currents

radiation

• the transfer of heat between 2 regions of different temperature without the need for a medium

  • radiation can be absorbed or emitted

factors that affect the rate of conduction

• type of material

  • good conductors

    • metals,

  • poor conductors

    • plastic, glass, fibre, air, liquids etc

factors that affect radiation

• colour

  • duller, dimmer colours are good conductors of radiation

  • brighter, shinier colours are poor conductors of radiation

• textures

  • rougher surfaces tend to have a larger surface area, therefore they are better conductors of radiation

  • smoother surfaces are poorer conductors of radiation

• temperature

  • regions with a higher temperature are good conductors of radiation

  • regions with a lower temperature are poorer conductors of radiation