Energy stores & systems

• What is the principle regarding energy in physics?

  Energy is never created or destroyed
• What does the principle of energy transfer imply?

  Energy is transferred between different forms and objects
• What are the different forms of energy?

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

  It is related to the temperature of an object
• What type of energy is associated with motion?

  Kinetic energy
• What is gravitational potential energy based on?

  It is based on an object's position in a gravitational field
• What is elastic potential energy?

  Energy held in an already stretched spring
• What is chemical energy?

  Energy held in chemical bonds
• What does magnetic energy do?

  It holds magnets to your fridge
• What is electrostatic energy?

  Energy that gives shocks when touching metal
• What is nuclear energy derived from?

  Breaking atoms apart
• How can energy be transferred between stores?

  Mechanically, electrically, by heating, or by radiation
• What is a system in physics?

  A collection of matter being studied
• What happens in an open system?

  It can exchange energy with the outside world
• What characterizes a closed system?

  No matter or energy can enter or leave
• What is the overall energy change in a closed system?

  The overall change is always zero
• How does energy transfer occur in a kettle?

  1. Electrical energy flows to the heating element
  2. Heating element transfers energy to water
  3. Water's thermal energy store increases
• What does "work done" refer to in energy transfer?

  Energy transferred when moving an object
• What are the two main types of work done?

  Mechanical and electrical work
• What is mechanical work done?

  Using a force to move an object
• What is electrical work done?

  Energy required to overcome resistance in wires
• How does friction do work on a train?

  It slows the train by transferring energy
• What happens to kinetic energy when a train slows down?

  It transfers to thermal energy stores