P1: Energy Changes in a System Physics GCSE

• What is defined as a system in physics?

  An object or group of objects
• How does defining a system in physics help?

  It narrows parameters to focus on relevance
• 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 if the table is removed?

  The apple will fall
• How is energy measured?

  In units of joules (J)
• What types of thermodynamic systems exist?

  Isolated, closed, or open
• 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 happens to energy when a change occurs in a system?

  • Energy is transferred between objects
  • Energy can move between different stores
• What does the principle of conservation of energy state?

  Energy cannot be created or destroyed
• What does conservation of energy imply for a closed system?

  Total amount of energy is constant
• What are the different energy stores?

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

  Moving objects
• When do objects gain energy in their gravitational potential store?

  When lifted through a gravitational field
• What happens to energy in the elastic potential store?

  Stored when objects are stretched or compressed
• What is the magnetic energy store associated with?

  Magnetic materials interacting with each other
• What does the electrostatic energy store involve?

  Charged objects interacting with each other
• How is energy transferred between stores?

  Via transfer pathways
• What is mechanical working?

  When a force acts on an object
• What is electrical working?

  A charge moving through a potential difference
• How is energy transferred by heating?

  From a hotter object to a colder one
• What are the steps to describe energy transfers in a system?

  1. Determine the initial energy store
  2. Identify the final energy store
  3. Identify the transfer pathway
• In a battery powering a torch, where does energy transfer from?

  From the chemical store of the battery
• In a battery powering a torch, where does energy transfer to?

  To the thermal store of the bulb
• What is the transfer pathway in a battery powering a torch?

  Electrical flow of charge around the circuit
• In a falling ball, where does energy transfer from?

  From the gravitational potential store
• In a falling ball, where does energy transfer to?

  To the kinetic store of the ball
• What is the transfer pathway for a falling ball?

  Mechanical due to weight acting over distance
• What happens to energy when a ball is thrown upwards?

  Transferred to the kinetic store of the ball
• What happens to energy as the height of a thrown ball increases?

  Transferred to its gravitational potential store
• What happens to energy when a moving object hits an obstacle?

  Energy in its kinetic store decreases
• What happens to energy when a vehicle accelerates?

  Transferred to the kinetic store of the car
• What happens to energy when a vehicle slows down?

  Transferred to the thermal store of surroundings
• How is energy transferred when boiling water in a kettle?

  By electrical working to the thermal store
• What is kinetic energy defined as?

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

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

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

  E = ½ × m × v