Work
• Work is energy transferred that causes the
  object to move in the direction of the
  force — no movement, no work.
• Formula for work: W = F x d
• Units:
  – Work – joule (J)
  – Force – newton (N)
  – Distance – meter (m) or depends on problem
• Power is the rate at which work is done
• Formula: P = W/t
• Units:
  – Power – watt (W)
  – Work – joule (J)
  – Time – seconds (depends on problem)
Machines
• Machine – device that makes work easier
  by changing the size or direction of the
  force
• Machines let you swap force for distance
  or distance for force….you still do the
  same amount of work
Levers – move from a fixed point
Pulleys – grooved wheel that holds
           rope or cable
Wheel and axle – 2 circular objects
of different sizes (wheel is larger)
Inclined plane – straight slanted
             surface
Wedge – two inclined planes that
            move
Screw – inclined plane wrapped
      around a cylinder
Compound machine – made of
more than one simple machine

Work and machines

  • 1.
    Work • Work isenergy transferred that causes the object to move in the direction of the force — no movement, no work. • Formula for work: W = F x d • Units: – Work – joule (J) – Force – newton (N) – Distance – meter (m) or depends on problem
  • 2.
    • Power isthe rate at which work is done • Formula: P = W/t • Units: – Power – watt (W) – Work – joule (J) – Time – seconds (depends on problem)
  • 3.
    Machines • Machine –device that makes work easier by changing the size or direction of the force • Machines let you swap force for distance or distance for force….you still do the same amount of work
  • 4.
    Levers – movefrom a fixed point
  • 5.
    Pulleys – groovedwheel that holds rope or cable
  • 6.
    Wheel and axle– 2 circular objects of different sizes (wheel is larger)
  • 7.
    Inclined plane –straight slanted surface
  • 8.
    Wedge – twoinclined planes that move
  • 9.
    Screw – inclinedplane wrapped around a cylinder
  • 10.
    Compound machine –made of more than one simple machine