Work Done

• Work Done


  Energy transferred between energy stores by doing work
• Energy can be Transferred by Doing Work
• Work done


  Another way of saying energy transferred, they're the same thing
• Work can be done


  1. When current flows (work is done against resistance in a circuit)

  2. By a force moving an object
• Examples of work done


  • The initial force exerted by a person to throw a ball upwards
  • Frictional forces causing a transfer of energy as a car slows down
  • The normal contact force between a car and a stationary object in a collision
• Some energy might also be transferred away by sound waves
• Falling Objects Also Transfer Energy


  1. Accelerated by gravity, the gravitational force does work

  2. Energy from the object's gravitational potential energy (g.p.e) store is transferred to its kinetic energy store

  3. For a falling object with no air resistance, energy lost from the g.p.e. store = energy gained in the kinetic energy store
• In real life, air resistance acts against all falling objects - it causes some energy to be transferred to other energy stores, e.g. the thermal energy stores of the object and surroundings