2.2

• work -

  • Work is done when a force acts on an object to make the object move
  • So MOVEMENT is needed before you can say work has been done
• • the amount of work depends on:
  • The amount of force exerted on the object
  • The distance the object moved in the direction of the applied force
• without energy, there would be no work

  • In a car, the energy to drive the wheels comes from the gasoline (energy source)
  • This provides the force that makes the work possible
  • The machine transfers energy from the source to the object, causing the object to move
• work and machines

  • Simple machines help us do work
  • But using a machine does not mean less work is done
  • You use the machine so you don’t have to exert as much force, but you still do the same amount of work
• friction and work,

  • Friction is the reason that work input does not equal work output in real situations
  • It affects a machine's efficiency