The Six Simple Machines

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The Six Simple Machines

• What they do And
• What they are For

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What is a Simple Machine?

• Simple Machines make Work easier
• Six Simple Machines Lever, Inclined Plane,
  Wedge, Screw, Wheel and Axle, and Pulley

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The Lever
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Simple Machine Lever

• Rigid Bar free to turn about a fulcrum
• Three Parts Resistance Force or Load, Effort
  Force, Fulcrum
• Three Classes of Levers First, Second, and Third

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Simple Machine First Class
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Simple Machine First Class

• Fulcrum located between Resistance and Effort
  Forces
• Resistance and Effort Forces are in opposite
  directions
• Examples Seesaw, Crowbars, Scissors, Claw
  Hammers

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Simple Machine Second Class
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Simple Machine Second Class

• Resistance Force is between the Effort Force and
  the Fulcrum
• Resistance and Effort Forces are in same
  direction
• Examples Wheelbarrow, Bottle openers, and
  Nutcrackers

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Simple Machine Third Class
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Simple Machine Third Class

• Effort Force is between the Resistance Force and
  the fulcrum
• Resistance and Effort Forces are in same
  direction
• Examples Broom, Shovel, Fishing Pole, Baseball
  Bat, and Tongs

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The Inclined Plane
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Simple Machine Inclined Plane

• Sloping surface allowing the lifting of heavy
  loads with less effort than directly lifting the
  load
• Examples Simple Ramp, Escalator, Stairs, Ship
  Plank, Ladder

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The Wedge
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Simple Machine - Wedge

• Form of an Inclined Plane tapering to a sharp
  edge
• Can be used to split, fasten, or cut
• Examples Ax Head, Screwdriver, Nails, Doorstop,
  Chisel, Plows

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The Screw
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Simple Machine - Screw

• Form of an Inclined Plane wrapped in a spiral
  around a cylindrical post to fasten things
• Two parts Body and Thread
• Examples Drill Bits, Jackscrew, Fan Blades,
  Propellers, Screw, Nuts Bolts

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The Wheel and Axle
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Simple Machine Wheel and Axle

• Wheel connected to a rigid pole
• Modified Lever and center of axle serves as
  Fulcrum
• Examples Door Knobs, Handle Bars on Bike,
  Wheels on car, Roller Conveyor

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Simple Machine Wheel and Axle

• Gears are modified forms of Wheel and Axle
• Wheel has teeth along circumference
• Effort Force exerted on larger gear to turn the
  smaller gear
• Examples Bike Sprockets, Can Opener, Machine
  Gears

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The Pulley
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Simple Machine - Pulley

• Grooved wheel turning around a fulcrum to lift
  heavy objects
• Rope or Chain used in groove
• Can be fixed, movable, or combination of both
• Examples Flag Pole to raise Flag, Hoisting a
  Sail, Open Curtains or Mini Blinds,

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Work

• Defined as a Force acting through a distance
• W F d
• Measured in Joules (J) after British Scientist
  James Prescott Joule

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Work

• Work is done only when
• Object moves, and
• Objects motion is in the direction of applied
  Force
• How does a Simple Machine make Work easier?

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References

• www.ask.com
• www.sirinet.net
• www.google.com