Dissipated Energy

• What does the principle of conservation of energy state?


  Energy cannot be created or destroyed.
• What happens to energy during a transfer?

  Energy is dissipated to forms that are not useful to us.
• What are the energy changes that occur within a car?

  • Input: Chemical energy from fuel
  • Main output: Kinetic energy for movement
  • Other outputs: Heat (due to friction and drag) and sound
  • Useful energy: Kinetic energy
  • Dissipated forms: Heat and sound
• What is the most common form of dissipated energy?


  Heat loss to the surroundings.
• What are the main causes of heat loss in a car?

  Resistance like drag and resistive forces like friction.
• Does heat loss occur in processes designed to transfer thermal energy?


  Yes, energy is lost due to heat flow with the surroundings.
• How can we determine the amount of dissipated energy in a transfer?


  By subtracting the useful output energy from the input energy.
• If an electric drill has an input of 900 Joules and a useful output of 850 Joules, what is the dissipated energy?


  50 Joules.
• What forms can dissipated energy take in an electric drill?


  • Heat in the drill bit
  • Heat in the moving parts
  • Sound from the drill
• What is the input energy for a helicopter that burns 1,000 Meg of fuel?


  1,000 Meg.
• What is the useful output energy gained by the helicopter?


  350 Meg of gravitational potential energy.
• How do you calculate the dissipated energy in the helicopter example?


  By subtracting the useful output from the input energy.
• What is the dissipated energy when a helicopter has an input of 1,000 Meg and a useful output of 350 Meg?


  650 Meg.
• What resources does Launchpad Learning offer for GCSE revision?


  • Interactive quizzes
  • Easy-to-follow videos
  • AI tutor support
  • Comprehensive coverage of specifications