energy stores and systems

• What is the fundamental principle regarding energy as stated in the video?

  Energy is never created or destroyed; it is only transferred between different forms and objects.
• What are the different forms of energy mentioned in the video?

  • Thermal or internal energy
  • Kinetic energy
  • Gravitational potential energy
  • Elastic potential energy
  • Chemical energy
  • Magnetic energy
  • Electrostatic energy
  • Nuclear energy
• What is thermal or internal energy related to?

  It is related to the heat energy trapped within an object and its temperature.
• What type of energy is associated with the movement of an object?

  Kinetic energy.
• What does gravitational potential energy depend on?

  It depends on the position of an object in a gravitational field.
• What is elastic potential energy?

  It is the energy held in an already stretched spring.
• What type of energy is associated with chemical bonds?

  Chemical energy.
• What is magnetic energy?

  It is the energy that holds magnets to your fridge.
• What is electrostatic energy responsible for?

  It occasionally gives you a shock when you touch your car.
• What is nuclear energy derived from?

  It is derived from breaking atoms apart.
• How can energy be transferred between different forms?

  • Mechanically (e.g., stretching an elastic band)
  • Electrically (e.g., plugging into a socket)
  • By heating
  • By radiation (e.g., light or sound waves)
• What happens in an open system?

  In an open system, matter can exchange energy with the outside world.
• What is meant by the term 'system' in physics?

  A system refers to a collection of matter being considered for energy transfer.
• What is a closed system?

  A closed system is separate from the outside world, so neither matter nor energy can enter or leave.
• What happens to energy in a closed system?

  The overall change in energy is always zero, even though energy can be transferred within the system.
• How does energy transfer occur when boiling water in a kettle?

  1. Electrical energy flows from the plug socket to the kettle's heating element.
  2. This energy is transferred to the thermal energy store of the heating element.
  3. The heating element then transfers energy to the water's thermal energy store.
• What is another way of saying 'energy transferred'?

  Work done.
• What are the two main types of work done?

  • Mechanical work done
  • Electrical work done
• What does mechanical work done involve?

  It involves using a force to move an object.
• What is an example of mechanical work done?

  Kicking a ball up in the air.
• What is electrical work done?

  It is done when current flows and overcomes resistance in the wires of a circuit.
• How does friction do work in the context of a train crossing a broken bridge?

  • Friction between the brakes and wheels slows the train down.
  • Energy in the wheels' kinetic energy stores is transferred to the thermal energy stores of the surroundings.
• What happens to the energy in the wheels of a train when it applies the brakes?

  Energy is transferred from the wheels' kinetic energy stores to the thermal energy stores of the surroundings.