Heat and Heat Transfer
HeatTemperatureConductionConvectionRadiation
Temperature•Hotness and coldness of a body•Related to the kinetic energy of the molecules
Heat
• Energy being transferred from one body to another
• Internal Energy • Sum of potential and kinetic energies
inside matter
Heat Transfer
• Heat energy flows from bodies with higher temperature to bodies with lower temperature
• Heat transfer occurs until both bodies have the same temperature • Thermal equilibrium
Heating does not always increase temperature.
•Change in the arrangement of particles•Change of phase•Potential energy
Conduction
• Direct transfer of energy through vibration of atoms
• Happens in solids• Mechanism
Conductor
• Material that allows heat or energy to pass through it (or conduct.)
• Metals: very good conductors• Good heat conductors are also good electrical
conductors.
Insulator
• Material that ________ heat to flow through• inhibit or does not allow • Conduct slowly
• Examples:• Plastic• Wood• Rubber
Convection
• Heat transfer by movement of particles or molecules
• Fluids (liquids and Gases)• Mechanism
• Convection current• Examples
Thermal Radiation
• Heat transfer without use of a medium
• Electromagnetic radiation• Infra-red radiation• Microwave
• Mechanism• Emission of electromagnetic
radiation
Surfaces and Radiation
• Black Surface• Good radiator, good absorber
• White surface• (Good reflector) bad absorber,
bad radiator• Silver Surface
• Very good reflector, bad absorber
Thermos Bottle or Vacuum Flask
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