The Six Simple Machines What they do And What they are For
What is a Simple Machine? Simple Machines make Work easier Six Simple Machines: Lever, Inclined Plane, Wedge, Screw, Wheel and Axle, and Pulley
The Lever
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
Simple Machine – First Class
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
Simple Machine – Second Class
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
Simple Machine – Third Class
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
The Inclined Plane
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
The Wedge
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
The Screw
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
The Wheel and Axle
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
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
The Pulley
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,
Work Defined as a Force acting through a distance W = F * d Measured in Joules (J) after British Scientist James Prescott Joule
Work Work is done only when Object moves, and Object’s motion is in the direction of applied Force How does a Simple Machine make Work easier?
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