Energy and Temperature Quiz

Energy and Temperature

• Temperature is a measure of how hot something is, measured in degrees Celsius (°C).
• Internal (thermal) energy is the amount of energy stored within a substance, measured in joules (J).
• The amount of thermal energy stored depends on the temperature, material, and mass of the object.
• Energy is transferred from hotter objects to cooler objects until they reach the same temperature.

Transferring Energy by Heating

• Evaporation: Fastest-moving particles escape a liquid and form a gas, lowering the temperature of the remaining liquid.
• Conduction: Heat transfer through direct contact, primarily in solids and liquids. Vibrations are passed between particles.
  • Metals are good conductors.
  • Liquids are poor conductors.
  • Gases are very poor conductors.
  • Thermal insulators are materials that resist heat transfer.
• Convection: Heat transfer in fluids (liquids and gases) due to density differences caused by heating. Heated fluid rises, cooler fluid replaces it, creating a convection current.
• Infrared Radiation: Energy transfer through space or transparent materials without the need for particles.
  • Hot objects emit infrared radiation.
  • Dark, dull surfaces are good absorbers and emitters of radiation.
  • Light, shiny surfaces are good reflectors and poor absorbers/emitters.

Power

• Power is the rate at which energy is transferred, measured in watts (W) or kilowatts (kW).
• 1 watt (W) is equal to 1 joule (J) of energy transferred per second.
• 1 kilowatt (kW) = 1000 watts (W).