heat and temperature

• Heat energy is transferred from one place to another by conduction, convection and radiation
• Three ways that we have changed or improved our heat technology over the years:

  cooking and heating, furnaces, clothes dryers, hair
• The pros and cons of Biomass electricity

  Pros: Renewable, plentiful

  Cons: inefficient, polluting
• Pros and cons of Geothermal energy

  Pros: Renewable, efficient, Non-polluting

  Cons: geographically limited
• P and C of hydro energy:

  Pros: renewable, efficient, Non polluting

  Cons: geographically limited
• P & c of Wind energy:

  Pros: Renewable, efficient, non-polluting

  Cons: Intermittent
• P & C of Solar energy:

  Pros: renewable, efficient, non-polluting

  Cons: Intermittent
• P & C of Fossil Fuels

  Pros: Plentiful

  Cons: polluting, non-renewable, inefficient
• difference between Passive solar heating and Active solar heating

  Passive solar heating: heating that uses materials in a structure to absorb, store and release solar energy

  Active solar heating: Uses mechanical and electrical equipment to enhance the conversion of solar energy to heat and electric power. (Solar collector)
• What is matter?

  Anything that takes up space, has mass, and is made up of particles.

  Ex: wood, air, steel
• What is energy?

  ability to cause change. Energy has no mass and does not occupy space. Not matter. Energy has the ability to move particles.

  Ex: Kinetic energy, thermal energy
• Explain expansion

  when particles increase in energy, the spaces between the particles increase.
• Do particles expand when heated?

  No. particles do not expand when heated - the spaces between particles expand.
• which state of matter expands the most?

  Gas will expand the most when energy is added because molecules within gases are further apart and weakly attracted to each other
• Why do bridges and railways need expansion gaps?

  bridges and tracks have gaps in them so that there is space for the particles of the concrete or metal to expand when there is more heat. There would be buckling on the surface is there wasn’t any
• Define heat in your own words.

  Thermal energy is transferred from one object to another because of a temperature difference. (stove heat to your hand)
• Define temperature in your own words

  a mesure of how cold or hot something is on a scale. The average energy (thermometer drawing)
• Define thermal energy in your own words

  The total kinetic energy or energy generated by the movement or vibration of particles (ice berg > pot of tea kinetic energy)
• What is absolute zero?

  Absolute zero is the temperature where no particles are moving, 273 degrees celsius
• How does a thermometer work?

  • thermometers usually contain alcohol
  • Heat causes the alcohol to expand and travel up the tube
  • Cooling causes the alcohol to contract and drop down the tube
• 3 ways that heat is transferred:

  conduction- thermal energy is transferred from one particle to the next, occurs in solides

  Convection- fluids move from place to place, carrying thermal energy. Occurs in fluids (liquids and gases)

  Radiation- transfer of energy without the movement of matter.
• where would you expect to find less dense gases or liquids in a convection current?

  gases near heat source and at top of current, less dense liquids away from heat source and near bottom
• What is radiation? how does it move?

  the transfer of energy without any movement of matter. it moves in wave or straight lines.
• Radiation examples:

  Sun heating up sand, homes