Conservation of Energy

• What is the law of conservation of energy?

  Energy cannot be created or destroyed.
• What is a closed system?

  A closed system is one where no energy is transferred to or from the surroundings.
• How do energy stores change in a closed system?

  The total energy remains constant, but energy can be transferred between different stores.
• What happens to the gravitational potential energy of a roller coaster as it climbs an incline?

  Its gravitational potential energy store increases.
• What happens to the gravitational potential energy of a roller coaster as it descends?

  Its gravitational potential energy store decreases.
• What happens to the kinetic energy store of a roller coaster as it descends?

  Its kinetic energy store increases.
• What are some ways energy is lost during a roller coaster ride?

  Energy is lost to thermal energy due to air resistance and friction, and by sound waves.
• Describe the energy transfers in a pendulum as it swings from one side to the other.

  • As it moves towards the middle:
  • Gravitational potential energy decreases
  • Kinetic energy increases
  • As it moves away from the middle:
  • Kinetic energy decreases
  • Gravitational potential energy increases
• What would happen to a pendulum in a vacuum?

  The pendulum would keep swinging forever without energy loss.
• What is the principle of conservation of energy?

  The total energy of a closed system is always the same before and after energy transfers.
• What happens to a bungee jumper's gravitational potential energy after jumping off the platform?

  It decreases as the jumper falls towards the ground.
• What happens to the kinetic energy store of a bungee jumper when the rope tightens?

  The jumper's kinetic energy store decreases.
• What happens to the elastic potential energy store of the rope when it stretches?

  The elastic potential energy store of the rope increases.
• What happens to the bungee jumper's kinetic energy store at the top of the ascent?

  The bungee jumper's kinetic energy store decreases to zero.
• Why doesn't the bungee jumper return to the original height?

  Some energy is transferred to the thermal energy store of the surroundings.
• What are the energy transfers that occur during a bungee jump?

  1. Gravitational potential energy to kinetic energy as the jumper falls.
  2. Kinetic energy to elastic potential energy as the rope tightens.
  3. Elastic potential energy to kinetic energy as the jumper rises.
  4. Kinetic energy to gravitational potential energy during ascent.
  5. Energy lost to thermal energy during stretching and shortening of the rope.
• What should you never use to describe kinetic energy?

  Never use the terms 'movement energy' or 'motion energy'.
• What safety precautions should be taken when testing a bungee jump experiment?

  Ensure the stand is secure and protect yourself from falling objects.
• What are the different types of energy stores mentioned in the material?

  Gravitational potential energy, kinetic energy, elastic potential energy, thermal energy.