The 6 Simple Machines

1
The 6 Simple Machines
Wedge
Screw
Inclined Plane
Pulley
Wheel and Axle
Lever
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Mechanical Advantage

• Mechanical advantage is the ratio of output force
  divided by input force. If the output force is
  bigger than the input force, a machine has a
  mechanical advantage greater than one.
• If a machine increases an input force of 10
  pounds to an output force of 100 pounds, the
  machine has a mechanical advantage (MA) of 10.
• In machines that increase distance instead of
  force, the MA is the ratio of the output distance
  and input distance.
• MA output/input

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Inclined Planes

• An inclined plane is a flat surface that is
  higher on one end
• Inclined planes make the work of moving things
  easier

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Inclined Plane -Mechanical Advantage

• The mechanical advantage of an inclined plane is
  equal to the length of the slope divided by the
  height of the inclined plane.
• While the inclined plane produces a mechanical
  advantage, it does so by increasing the distance
  through which the force must move.

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WHEEL AND AXLE

• The axle is stuck rigidly to a large wheel. Fan
  blades are attached to the wheel. When the axle
  turns, the fan blades spin.

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GEARS-Wheel and Axle

• Each gear in a series reverses the direction of
  rotation of the previous gear. The smaller gear
  will always turn faster than the larger gear.
• Mechanical advantage can also be found by
  comparing the teeth of each gear, input teeth /
  output teeth

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The Lever

• Lever, is one of the six simple machines for
  performing work. It consists of a rod or bar that
  rests and turns on a support called a fulcrum. A
  force of effort is applied at one end of the rod
  to lift a load placed at the other end. A lever
  can help lift a weight with less effort. Prying
  something loose with a crowbar is using a lever.
  Some machines, such as a catapult, use a lever to
  hurl objects.

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Three Classes of Levers

• First-class levers the fulcrum is in the
  middle like a seesaw,crowbar, or balance scale.
• Second-class levers- the load is in the middle
  like a wheel barrow, or a nutcracker.
• Third-class levers the effort is in the
  middle like a broom or a rake.

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Screw

• Screw is an inclined plane wrapped in a spiral
  around a shaft. The screw is one of the six
  simple machines developed in ancient times.

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Wedge

• Wedge is a device that has two or more sloping
  surfaces that taper either to a sharp edge or to
  a point. Wedges are used to split or pierce
  materials, and to adjust the positions of heavy
  objects. Knives, chisels, axes, pins, needles,
  and nails are wedges.

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