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By: Christina Widder

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By, the ancient Greek mathematician, Archimedes. ... 'Castle Rock State Park River.' Online Image. 13 Aug. 2006. Rock River. Oct. 2006. ... – PowerPoint PPT presentation

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Title: By: Christina Widder


1
Levers in History
  • By Christina Widder

2
A lever is…
  • A simple machine.
  • A rigid bar pivoted about a fulcrum.
  • Broken up into three classes.

3
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

6
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.

7
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.

8
Ancient Egyptians
  • Egyptians also used levers to move water from
    rivers.

9
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.

10
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.

11
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.

12
Ancient Romans
  • The catapults were used to throw large rocks at
    their enemies.
  • Catapults helped the Romans defeat many armies.

13
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.

14
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.

15
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.

16
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.

17
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

18
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

19
THE END!
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