The Six Simple The Six Simple MachinesMachines

What they do And What they do And

What they are ForWhat they are For

What is a Simple What is a Simple Machine?Machine?

• Simple Machines make Work easierSimple Machines make Work easier

• Six Simple Machines: Lever, Six Simple Machines: Lever, Inclined Plane, Wedge, Screw, Inclined Plane, Wedge, Screw, Wheel and Axle, and PulleyWheel and Axle, and Pulley

The LeverThe Lever

Simple Machine – LeverSimple Machine – Lever

• Rigid Bar free to turn about a Rigid Bar free to turn about a fulcrumfulcrum

• Three Parts: Resistance Force or Three Parts: Resistance Force or Load, Effort Force, FulcrumLoad, Effort Force, Fulcrum

• Three Classes of Levers: First, Three Classes of Levers: First, Second, and ThirdSecond, and Third

Simple Machine – First Simple Machine – First ClassClass

Simple Machine – First Simple Machine – First ClassClass

• Fulcrum located between Fulcrum located between Resistance and Effort ForcesResistance and Effort Forces

• Resistance and Effort Forces are in Resistance and Effort Forces are in opposite directionsopposite directions

• Examples: Seesaw, Crowbars, Examples: Seesaw, Crowbars, Scissors, Claw HammersScissors, Claw Hammers

Simple Machine – Second Simple Machine – Second ClassClass

Simple Machine – Second Simple Machine – Second ClassClass

• Resistance Force is between the Resistance Force is between the Effort Force and the FulcrumEffort Force and the Fulcrum

• Resistance and Effort Forces are in Resistance and Effort Forces are in same directionsame direction

• Examples: Wheelbarrow, Bottle Examples: Wheelbarrow, Bottle openers, and Nutcrackersopeners, and Nutcrackers

Simple Machine – Third Simple Machine – Third ClassClass

Simple Machine – Third Simple Machine – Third ClassClass

• Effort Force is between the Effort Force is between the Resistance Force and the fulcrumResistance Force and the fulcrum

• Resistance and Effort Forces are in Resistance and Effort Forces are in same directionsame direction

• Examples: Broom, Shovel, Fishing Examples: Broom, Shovel, Fishing Pole, Baseball Bat, and TongsPole, Baseball Bat, and Tongs

The Inclined PlaneThe Inclined Plane

Simple Machine – Simple Machine – Inclined PlaneInclined Plane

• Sloping surface allowing the lifting Sloping surface allowing the lifting of heavy loads with less effort than of heavy loads with less effort than directly lifting the loaddirectly lifting the load

• Examples: Simple Ramp, Escalator, Examples: Simple Ramp, Escalator, Stairs, Ship Plank, LadderStairs, Ship Plank, Ladder

The WedgeThe Wedge

Simple Machine - WedgeSimple Machine - Wedge

• Form of an Inclined Plane tapering Form of an Inclined Plane tapering to a sharp edgeto a sharp edge

• Can be used to split, fasten, or cutCan be used to split, fasten, or cut

• Examples: Ax Head, Screwdriver, Examples: Ax Head, Screwdriver, Nails, Doorstop, Chisel, PlowsNails, Doorstop, Chisel, Plows

The ScrewThe Screw

Simple Machine - ScrewSimple Machine - Screw

• Form of an Inclined Plane wrapped Form of an Inclined Plane wrapped in a spiral around a cylindrical post in a spiral around a cylindrical post to fasten thingsto fasten things

• Two parts: Body and ThreadTwo parts: Body and Thread

• Examples: Drill Bits, Jackscrew, Fan Examples: Drill Bits, Jackscrew, Fan Blades, Propellers, Screw, Nuts & Blades, Propellers, Screw, Nuts & BoltsBolts

The Wheel and AxleThe Wheel and Axle

Simple Machine – Wheel Simple Machine – Wheel and Axleand Axle

• Wheel connected to a rigid poleWheel connected to a rigid pole• Modified Lever and center of axle Modified Lever and center of axle

serves as Fulcrumserves as Fulcrum

• Examples: Door Knobs, Handle Bars Examples: Door Knobs, Handle Bars on Bike, Wheels on car, Roller on Bike, Wheels on car, Roller ConveyorConveyor

Simple Machine – Wheel Simple Machine – Wheel and Axleand Axle

• Gears are modified forms of Wheel and Gears are modified forms of Wheel and AxleAxle• Wheel has teeth along circumferenceWheel has teeth along circumference

• Effort Force exerted on larger gear to Effort Force exerted on larger gear to turn the smaller gearturn the smaller gear

• Examples: Bike Sprockets, Can Opener, Examples: Bike Sprockets, Can Opener, Machine GearsMachine Gears

The PulleyThe Pulley

Simple Machine - PulleySimple Machine - Pulley

• Grooved wheel turning around a Grooved wheel turning around a fulcrum to lift heavy objectsfulcrum to lift heavy objects• Rope or Chain used in grooveRope or Chain used in groove

• Can be fixed, movable, or combination Can be fixed, movable, or combination of bothof both

• Examples: Flag Pole to raise Flag, Examples: Flag Pole to raise Flag, Hoisting a Sail, Open Curtains or Mini Hoisting a Sail, Open Curtains or Mini Blinds, Blinds,

WorkWork

• Defined as a Force acting through a Defined as a Force acting through a distancedistance

• W = F * dW = F * d

• Measured in Joules (J) after British Measured in Joules (J) after British Scientist James Prescott JouleScientist James Prescott Joule

WorkWork

• Work is done Work is done onlyonly when when• Object moves, andObject moves, and• Object’s motion is in the direction Object’s motion is in the direction

of applied Forceof applied Force

• How does a Simple Machine make How does a Simple Machine make Work easier?Work easier?

ReferencesReferences

• www.ask.comwww.ask.com

• www.sirinet.netwww.sirinet.net

• www.google.comwww.google.com