| A | B |
|---|
| Temperature | measure of average Kinetic energy of particles in an object or substance |
| thermal energy | sum of kinetic and potential energy of particles in an object or substance |
| mass and thermal energy | if temperature remains constant, thermal energy increases as mass increases |
| heat | thermal energy that flows from something at a higher temperature to something at a lower temperature |
| specific heat | amount of heat needed to raise the temperature of 1 kg. of material 1 degree celsius (the higher the specific heat, the greater the heat needed to raise its temperature) |
| calorimeter | instrument that measures the specific heat of a substance |
| formula for calculating change in thermal temperature | Q=(mass)(change in temperature)(specific heat) |
| 3 ways to transfer thermal energy | conduction, convection, radiation |
| conduction | transfer of thermal energy by collisions between particles in matter (which are in constant motion); transfer occurs by collisions between particles of matter, not by movement of matter |
| rate of conduction | faster in solids and liquids, slower in gases; best conductors are metals |
| convection | transfer of thermal energy in a fluid (liquid or gas) by the movement of fluid particles from place to place |
| temperature and density | generally, the higher the temperature of a substance, the farther apart the particles of the substance and thus the lower the density |
| convection current | the rising and sinking action that occurs (due to changes in density) as currents transfer heat from warmer to cooler parts |
| difference between conduction and convection | in conduction, heated particles collide with each other and transfer energy; in convection, fluid particles move from place to place and carry their energy with them |
| radiation | transfer of energy by electromagnetic waves (not dependent on presence of matter); not to be confused with nuclear radiation |
| radiant energy | energy that is transferred by radiation |
| insulator | a material in which heat flows slowly (examples: wood, some plastic, air); used to reduce the rate of heat transfer |
| 4 common types of home heating systems | forced air, radiator, electric, solar (passive and active); all require source of energy |
| passive solar heating system | materials inside building absorb radiant energy from Sun during day; helps retain warmth at night |
| active solar heating system | use solar collectors installed on roof or south side of building; collected energy then circulated through building |
| thermodynamics | relationship between thermal energy, heat and work |
| First Law of Thermodynamics | the increase in thermal energy of a system equals the work done on the system plus the heat transferred to the system (the increase in energy of a system = the energy added to the system);when a transfer of thermal energy occurs, the increase in thermal energy of a cooler object = the decrease in energy of the warmer object |
| Second Law of Thermodynamics | Work must be done in order for heat to transfer from a cooler object to a warmer object.(example: a refrigerator which does work to move heat from inside the refrigerator to the warmer room); heat cannot be converted completely into work |
