Energy Stores

Energy and its Forms

  • Energy is transferred between different forms and objects.

  • Forms of energy include thermal, kinetic, gravitational potential, elastic potential, chemical, magnetic, electrostatic, and nuclear energy.

  • Energy can be transferred between these forms mechanically, electrically, through heating, or radiation.

Collection of Matter

  • A system is a collection of matter in physics.

  • Energy is transferred within a system or between objects/forms.

  • In an open system, energy can exchange with the outside world, while a closed system is isolated.

  • In a closed system, energy transfer within the system results in an overall zero change.

Examples

  • Example with a kettle illustrates energy transfer from electrical to thermal energy.

  • Work done is another term for energy transferred, with mechanical and electrical work being key types.

  • Mechanical work involves using force to move objects, while electrical work is overcoming resistance in circuits.

Practice

  • Example of a train applying brakes to slow down, transferring kinetic energy to thermal energy.

  • Friction between brakes and wheels causes energy transfer.

  • Energy stores change as work is done, affecting the system's energy balance.