What is Energy?

Energy is the ability a system has to produce changes on another system.


A system is a set of interacting or interdependent system components forming an integrated whole.

Systems Characteristics

  1. Systems have structure, defined by components and their composition.
  2. Systems have behavior, which involves inputs, processing and outputs of material, energy, information, or data.
  3. Systems have interconnectivity: the parts of a system have functional and structural relationships.
  4. Systems may have some functions or groups of functions

Types of systems

  1. An open system is a system which continuously interacts with its environment.
  2. An isolated system (closed) is a physical system that does not interact with its surroundings.
    • An isolated system obeys conservation laws: its total energy and mass stay constant.

Energy form(s)

Three Big Ideas

  1. All physical events involve transferring energy or changing one form of energy into another (transforming).
  2. Whenever energy is reduced in one place, it is increased somewhere else by exactly the same amount.
  3. Whenever there is a transformation of energy, some of it is likely to go into heat which spreads around and is therefore not available for use.

Energy Transfer

A system can transfer energy by means of three ways:

  1. physical or thermodynamical work
  2. heat transfer
  3. mass transfer
  1. place / time / event
  2. form of energy
  3. place / time / event

Energy Transformation

  1. form of energy
  2. place / time / event
  3. form of energy