Levers and Pulleys

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Levers and Pulleys
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• 1. pulley - simple machine consisting of a chain,
  belt or rope wrapped around a wheel

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2.TwoTypes of Pulleys
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3. Fixed Pulleys

• attached to a structure
• changes the direction of the input force
• example window blinds

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4. Movable Pulleys

• attached to the object you are moving
• multiplies the effort of the input force
• example - construction crane

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5. Block and TackleCombination of fixed and
movable pulleys
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PULLEYS

• What else can you think of that uses a pulley?

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6. Levers

• simple machine in which
• a bar is free to pivot on a fixed point

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• 7. that fixed point is
• called a fulcrum
• example - base of a see-saw

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• 8.Three Types

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9. 1st class

• input force
• fulcrum
• output force

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10.1st class

• increases the distance of the input force
• changes the direction of the input force
• example - scissors

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11. 2nd class

• fulcrum
• output force
• input force

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12.2nd class

• increases the input force
• does not change the direction of the input force
• example - door

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13.3rd class

• fulcrum
• input force
• output force

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14.3rd class

• increases the distance of the input force
• does not change the direction of the input force
• example baseball bat

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Levers

• What are some more examples of levers?