1.2 National & Global Energy Resources

• What is defined as a system in physics?

  An object or group of objects
• What happens when a system is in equilibrium?

  Nothing changes and nothing happens
• What occurs when there is a change in a system?

  Energy is transferred
• What happens to an apple when the table is removed?

  The apple falls due to gravity

  
• How is energy measured?

  In units of joules (J)
• What are the three types of thermodynamic systems?

  Open, closed, and isolated

  
• What is an open system?

  Allows exchange of energy and matter

  
• What is a closed system?

  Can exchange energy but not matter

  
• What is an isolated system?

  Does not allow transfer of matter or energy

  
• What does the principle of conservation of energy state?

  Energy cannot be created or destroyed
• What happens to the total amount of energy in a closed system?

  It remains constant
• What are the different energy stores?

  • Kinetic
  • Gravitational potential
  • Elastic potential
  • Magnetic
  • Electrostatic
  • Chemical
  • Nuclear
  • Thermal
• What is kinetic energy?

  Energy of moving objects
• What is gravitational potential energy?

  Energy due to an object's height
• What is elastic potential energy?

  Energy stored when objects are deformed
• What is magnetic energy?

  Energy in magnetic materials interacting
• What is electrostatic energy?

  Energy in charged objects interacting
• What is chemical energy?

  Energy transferred in chemical reactions
• What is nuclear energy?

  Energy released during nuclear reactions
• What is thermal energy?

  Energy all objects have due to temperature
• What are the energy transfer pathways?

  • Mechanically
  • Electrically
  • By heating
  • By radiation
• What is mechanical working?

  Energy transfer when a force acts on an object
• What is electrical working?

  Energy transfer by charge moving through potential difference
• What is heating by particles?

  Energy transfer from hot to cold objects
• What is heating by radiation?

  Energy transfer by electromagnetic waves
• What is an example of energy transfer?

  Hot coffee heating cold hands
• What are the energy transfers in a battery powering a torch?

  1. Energy from chemical store of battery
  2. Transferred to thermal store of bulb
  3. Transfer pathway is electrical

  
• What are the energy transfers when a ball falls?

  1. Energy from gravitational potential store
  2. Transferred to kinetic store
  3. Transfer pathway is mechanical
• What is the energy transfer when a vehicle accelerates?

  Energy from chemical store to kinetic store
• What happens when a vehicle slows down?

  Energy is transferred to the thermal store
• What energy transfer occurs when boiling water in a kettle?

  Electrical energy to thermal store of water
• What is kinetic energy defined as?

  Energy due to mass and speed
• What happens to kinetic energy when an object speeds up?

  Energy is transferred to its kinetic store
• What happens to kinetic energy when an object slows down?

  Energy is transferred away from its kinetic store
• What is the equation for kinetic energy?

  E = ½ × m × v²
• How do you calculate kinetic energy?

  Use E = ½ × m × v²
• What is the kinetic energy of a 1200 kg vehicle moving at 27 m/s?

  440,000 J
• What is gravitational potential energy defined as?

  Energy due to an object's height
• What happens to gravitational potential energy when an object is lifted?

  Energy is transferred to its gravitational potential store
• What happens to gravitational potential energy when an object falls?

  Energy is transferred away from its gravitational potential store