Conservation of Energy

• What is the formula for change in gravitational potential energy (GPE)?

  ∆𝐺��𝐸 = 𝑚𝑔∆ℎ
• What does the equation ∆𝐺𝑃𝐸 = 𝑚𝑔∆ℎ calculate?

  Change in gravitational potential energy
• What units are used for gravitational potential energy?

  Joules (J)
• What does the change in gravitational potential energy depend on?

  Mass, gravitational field strength, and height
• What is the formula for kinetic energy (KE)?

  𝐾𝐸 = \frac{1}{2}𝑚𝑣^2
• What does the kinetic energy formula calculate?

  Energy associated with a moving object
• What units are used for kinetic energy?

  Joules (J)
• What do energy transfer diagrams show?

  • Energy input and output
  • Forms of energy
  • Waste output energy
• What happens to kinetic energy (KE) when an object is projected upwards?

  KE is transferred to gravitational potential energy (GPE)
• What occurs when an object is projected up a slope?

  KE is transferred to GPE and heat
• What happens when a moving object hits an obstacle?

  KE is transferred to sound or the obstacle
• What does it mean when work is done on an object?

  The object gains kinetic energy (KE)
• What happens to kinetic energy (KE) when a vehicle slows down?

  KE is transferred to heat through brakes
• What energy transformation occurs when boiling water in a kettle?

  Electrical energy is converted to thermal energy
• What does conservation of energy state?

  Total energy of an isolated system remains constant
• What is a closed system?

  No external forces acting on it
• What happens to total energy in a closed system?

  Total energy never changes despite transfers
• What occurs when a system becomes open?

  Energy can be transferred out of the system
• What happens in mechanical processes regarding energy?

  Energy can cause a rise in temperature
• How is energy dissipated in mechanical processes?

  Heat is transferred to surroundings
• What are common forms of waste energy?

  • Light
  • Sound
  • Heat
• How can waste energy be reduced?

  By lubricating systems and thermal insulation
• What is the effect of thicker walls in buildings?

  Greater thermal insulation reduces heat loss
• What is cavity wall insulation used for?

  To prevent air flow and heat loss
• How is efficiency defined?

  Ratio of useful output to total input
• How can efficiency be increased?

  By reducing waste output and recycling
• What are some energy sources?

  • Fossil Fuels
  • Nuclear Fuel
  • Bio-Fuel
  • Wind
  • Hydro-electricity
  • Tidal
  • Solar
• Why are non-renewable energy sources used more for large-scale supplies?

  They provide large energy output per kilogram
• Why has renewable energy become more important?

  Due to the finite lifetime of fossil fuels
• What trend occurred during the industrial revolution regarding energy sources?

  Fossil fuels became an important energy source
• What has changed regarding renewable energy since the industrial revolution?

  Technology has developed to harness it efficiently