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30 Cards in this Set
- Front
- Back
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Lever
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A bar that is free to pivot or turn at a fixed point (fulcrum) like a crowbar or seesaw.
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Pulley
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A simple machine that consists of a wheel with a groove in the rim where a rope fits into the groove. Example: elevator.
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Fixed pulley
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a wheel and rope that is attached and doesn't move. It changes the direction of the effort force; however, the input force must equal the load.
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Block & Tackle
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System of pulleys consisting of fixed & moveable pulley. |
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Wheel & Axle
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A large-diameter wheel rotates in a circle around a small-diameter axle. Shaft or axle attached to a larger wheel such as door knobs, screwdrivers, faucet handles, pencil sharpener. |
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Inclined Plane
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A flat, sloping surface makes it easier to move heavy objects to higher levels. The principle behind inclined planes is to spread the force out over a longer distance. Example: wheelchair ramp, loading ramps for warehouses and gangplanks for ships. |
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Joules
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What energy and work are measured by.
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Mechanical Advantage
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Input force _____________ output force |
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Screw
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An inclined plane wrapped in a spiral around a cylinder or cone. Example: winding mountain road, drills, corkscrews or the lid of a jar.
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Wedge
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An inclined plane with two sides that is used as a tool for cutting or separating things like a needle, bolt, ax blade, log splitter or a knife.
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effort arm of the lever
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The part of the lever you apply an input effort force.
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resistance arm of the lever
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Simple Machines
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Devices with a few moving parts that make work easier to do. They lower the force needed to move and lift heavy objects and loads.
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In the lever, the ___________ force produced depends on the ______________ of the arm.
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output, length |
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Six types of simple machines |
Lever, Inclined Plane, Screw, Pulley, Wheel & Axle, Wedge
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Three classes of levers
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First-Class Levers, Second-Class Levers, and Third-Class Levers
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What class lever increases the speed and distance over which a force acts and include fishing rods, tweezers and baseball bats?
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Third-Class Lever
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What class lever changes the direction of the force and includes seesaws, scissors, crowbars and rowboat oars?
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First-Class Lever
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What class lever increases the force used and include wheel barrows, bottle opener and nutcrackers?
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Second-Class Levers |
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Movable Pulley
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Decreases the effort force needed to move the load because the rope moves a long distance to move the load a short distance. |
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How does a small input force become a big output force?
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The effort force is multiplied when the effort arm is longer than the resistance arm.
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The _________steep the slope of the effort arm, the _________effort is needed to move the load up the ramp.
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less, less; more, more
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Complex Machines
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Simple machines are combined to form this.
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________________ pulleys multiply force.
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Moveable
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The slanted surface is the _________________arm. The vertical end of the plane is the _____________ arm.
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effort or input, output
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Block & Tackle
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System of pulleys consisting of fixed & moveable pulleys. Basically, the weight of the object is spread over multiple ropes, meaning less force needs to be applied to raise it. |
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In a wheel and axle, you can increase the ____________________________by using a larger wheel.
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Mechanical Advantage
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Gear
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Multiple wheels that interlock together, one turn of a larger wheel causes the smaller wheel to turn multiple times.
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The inclined plane is less efficient due to the force of ____________________________.
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Friction
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a simple machine uses force to do _____________ against a _________________ of force.
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work, single load
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