By: Christina Widder

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Levers in History

• By Christina Widder

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A lever is

• A simple machine.
• A rigid bar pivoted about a fulcrum.
• Broken up into three classes.

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Three Classes of Levers
A first class lever is the most common type of
lever.
4
First Documented Knowledge of levers

• Was in 260 B.C.
• By, the ancient Greek mathematician, Archimedes.
• In this picture a first class lever is being
  used.

5
When was the first lever made?

• The real answer is uncertain.
• But it is believed that the first use of levers
  used trees to move heavy rocks.
• Once again a first class lever is being used in
  the picture to the right

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Ancient Egyptians

• Levers helped build the pyramids.
• Levers were used to lift large rocks for
  building.
• Then they used other simple machines to transport
  those rocks.

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Ancient Egyptians

• It was estimated that it took about 30 years to
  build the pyramids with levers and other simple
  machines.
• But what if levers did not exist then?
• Image how long it would have taken to build the
  pyramids, if it was even possible.

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Ancient Egyptians

• Egyptians also used levers to move water from
  rivers.

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Ancient Egyptians

• This would be a lever with a counterweight.
• The weight being on the opposite side of the
  bucket would make it easier to lift the water.

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Ancient Egyptians

• After the water is lifted, the pole is moved to
  the other side where the water can be put into
  the channel, which is then more accessible.
• It was estimated that one person could lift 2,500
  liters of water a day.
• Without a lever a person probably wouldnt be
  able to lift as much water.

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Ancient Romans

• The first simple catapult was invented in Ancient
  Greece.
• But the Romans used levers in making catapults
  with wheels, along with other simple machines.

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Ancient Romans

• The catapults were used to throw large rocks at
  their enemies.
• Catapults helped the Romans defeat many armies.

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Modern Scissors

• Are made from two cross-blades that pivot around
  a fulcrum (two levers).
• Were invented in ancient Rome around A.D. 100.
• Scissors were typically used to make clothing.

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Wheelbarrow

• The Chinese were credited for the invention of
  the wheelbarrow in A.D. 100.
• The wheelbarrow is a second class lever, but also
  has a wheel and axle.
• Was used to transport rocks, or even medical
  supplies during wars.

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Your Arm is a lever

• The fulcrum would be the elbow, the effort is the
  muscle, and the load is in the hand.
• This is a third class lever.
• It is unknown how long humans have been around,
  but we know that it has been for many, many years.

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Conclusion

• Levers have been helpful and important throughout
  history.
• Levers help decrease the effort it takes to move,
  lift, and etc
• There are many other types levers that were used
  in the past and are still present today only a
  few were mentioned here.

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Work Cited

• Archimedes. Oct. 2006 lthttp//www.sciencetrek.net/
  archimedes
• .htmgt
• Catapults. Online Image. Hardware.fr. Oct.
  2006. http//us.games2.yimg.com
• Castle Rock State Park River. Online Image. 13
  Aug. 2006. Rock River. Oct. 2006.
  http//pages.ripco.net/jwn/rock.jpg
• Col, Jeananda. Levers Simple Machines. Enchanted
  Learning. Oct. 2006 lthttp//www.enchantedlearning.
  com/physics/machines/
• Levers.shtmlgt
• Col, Jeananda. Zoom Inventors and Inventions.
  Enchanted Learning. Oct. 2006 lthttp//www.enchante
  dlearning.com
• /physics/machines/Levers.shtmlgt
• Egyptian Pyramid. Online Image. A Visit to the
  Pyramids Oct. 2006. lthttp//members.cox.net/ancie
  nt-sites/egypt/Pyramid_and_Sphinx.JPGgt

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Work Cited Continued

• History of Levers. Science Technology and
  Engineering. Oct. 2006 lthttp//www.enged.com.au/s
  tudents/mecsys/mecsys17.htmlgt
• Johnson, Jerry. Simple machines, work Physical
  Science. Oct. 2006. lthttp//www.sirinet.net/jgjo
  hnso/simple.htmlgt
• McKee, Jeffery. Lever. Online Image. Science of
  Evolution. Oct. 2006. lthttp//home.insight.rr.com/
  jkmckee/lever.jpggt
• Roman Scissors. Online Image. Oct. 2006
  lthttp//www.petrie.ucl.ac.uk/detail/Images/72/UC36
  207.jpggt
• Simple Machines. 7 Oct. 2006. School for
  Champions. Oct. 2006 http//www.school-for-champi
  ons.com/science/machines.htm
• Third Class. Engine Mechanics. Oct. 2006.
  lthttp//www.tpub.com/machines/1b.htmgt
• Wheelbarrow. 7 Oct. 2006. Wikipedia. Oct. 2006.
  lthttp//en.wikipedia.org/wiki/Wheelbarrowgt

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THE END!