work done and energy transfer

• What is the equation for work done, in joules (J)?

  work done = force x distance
• What happens when a force moves an object through a distance?


  When a force moves an object through a distance, energy is transferred and work is done on the object (e.g. when a resultant force moves an object, work is done) -> a rise in temperature of the object
• What does it mean if all forces combine on an object to give a resultant force of zero?


  Object is in equilibrium
• One joule of work is done when 


  a force of one newton causes a displacement of one metre.
• a force does work on an object when the force causes a displacement of the object.
• 1 joule = 1 newton-metr
• Work done against the frictional forces acting on an object causes a 


  rise in the temperature of the object.
• What is a key thing about the distance?

  distance must be in the line of force