Conservation/Energy

• What does the principle of conservation of energy state?


  Energy cannot be created or destroyed.
• How is energy transferred between a battery and a bulb?


  The battery converts chemical energy into electrical current.
• What happens to energy when it is converted from one form to another?


  The total energy in a closed system remains the same.
• What is a closed system?


  A closed system has the same total energy after any energy transfer.
• What is an open system?


  An open system can bring in or give away energy.
• How does a kettle demonstrate energy transfer?

  Electrical energy is converted to thermal energy in the water.
• What happens to the kinetic energy of an apple when it is tossed into the air?


  The kinetic energy decreases and converts into gravitational potential energy.
• What does GP stand for in the context of energy?


  GP stands for gravitational potential energy.
• What happens to gravitational potential energy as the apple falls?


  Gravitational potential energy decreases and converts back into kinetic energy.
• What additional energy conversion occurs when the apple collides with air molecules?


  Some energy is converted to heat, warming the apple and surrounding air molecules.
• How can we mathematically express the conservation of energy in a closed system?


  The total energy before a transfer equals the total energy after a transfer.
• In the example of a plane taking off, what is the input of chemical energy?


  The input of chemical energy is 120 Meg.
• How much kinetic energy is produced when the plane takes off?


  The plane produces 30 Meg of kinetic energy.
• What is the total energy after the transfer in the plane example?


  The total energy after the transfer is equal to 120 Meg.
• How much gravitational potential energy is gained by the trolley in the example provided?


  The trolley gains 80 Joules of gravitational potential energy.
• How do we calculate the kinetic energy gained by the trolley?

  Kinetic energy is calculated as total energy before transfer minus gravitational potential energy.
• What is the total energy before the transfer for the trolley example?


  The total energy before the transfer is 250 Joules.
• What is the kinetic energy gained by the trolley after the transfer?


  The trolley gains 170 Joules of kinetic energy.
• What are the key components of energy transfer in the examples provided?


  • Energy cannot be created or destroyed.
  • Energy can be stored, transferred, or changed in form.
  • Closed systems maintain total energy.
  • Open systems can exchange energy.
  • Examples include kettles, tossing apples, and planes taking off.
• What are the steps to calculate energy changes in a system?


  1. Identify total energy before transfer.
  2. Identify energy forms after transfer.
  3. Apply conservation of energy principle.
  4. Calculate kinetic energy or other forms as needed.