Dissipation of energy

• What is the conservation of energy?

  Energy cannot be created nor destroyed only transferred.
• How is energy dissipated?

  Most of the time energy is wasted as thermal energy, for example due to friction or a wire heating up
• What is the relation between GPE and KE?

  When something is going up the kinetic energy will decrease whereas the gravitational potential energy will increase because it is being raised. When something is going down the gravitational energy will decrease whereas the kinetic energy will increase because it is moving.
• What is a diagram of useful energy and wasted energy called?

  Sankey diagram
• In a gragh the kinetic energy is at 10 and the gravitational potential energy is at 0. What will the total energy be at? Why?

  10. The total energy is the sum of kinetic and gravitational potential energy. The total energy will never change.
• A crane lifts steel pipes up to the top if a building site. At the top the pipes have 27,000J of gravitational potential energy. The crane applies a force of 500N and lifts the pipes 80m. How would you calculate the energy wasted by the crane?

  First you would calculate the total energy used by using the calculation,

  Work done = Force × Distance.

  500 × 80 = 40,000J.

  Then you would fine the wasted energy by doing,

  Total energy - Useful energy = Wasted energy

  40,000J - 27,000J = 13,000J