conservation of energy

• What is the conservation of energy principle?

  Energy can be transferred, stored, or dissipated
• What does the conservation of energy principle imply about energy?

  Energy cannot be created or destroyed
• How does charging a phone illustrate the conservation of energy principle?

  Electrical energy converts to chemical energy in the battery
• What happens to chemical energy when you use your phone?

  It converts back to electrical energy
• What type of energy does the phone's screen convert electrical energy into?

  Light energy
• What type of energy does the phone's speaker convert electrical energy into?

  Sound energy
• What is meant by wasted energy in energy transfers?

  Energy not transferred to the desired store
• What is the common form of wasted energy?

  Heat energy
• Why might a phone warm up during charging?

  Due to wasted energy in the form of heat
• What is a system in physics?

  A portion of the physical universe analyzed
• What is the environment in relation to a system?

  Everything outside the chosen system
• Why is the phone considered an open system?

  Energy and matter can move freely with the environment
• What happens to heat energy when the phone is in a sealed jar?

  It dissipates to the air inside the jar
• What is a closed system in physics?

  A system where energy and matter cannot escape
• How does the overall energy of a closed system behave?

  It doesn't change
• What are the key concepts of the conservation of energy principle?

  • Energy can be transferred, stored, or dissipated
  • Energy cannot be created or destroyed
  • Energy moves between different objects and forms
• What are the energy transformations when charging and using a phone?

  1. Electrical energy to chemical energy (charging)
  2. Chemical energy to electrical energy (using)
  3. Electrical energy to light energy (screen)
  4. Electrical energy to sound energy (speaker)
• What distinguishes open systems from closed systems?

  • Open systems: Energy and matter can move freely
  • Closed systems: Energy and matter cannot escape