1. No category

By: Christina Widder
A lever is…
• A simple machine.
• A rigid bar pivoted
about a fulcrum.
• Broken up into three
classes.
Three Classes of Levers
A first class lever is the most common type of lever.
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.
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
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.
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.
Ancient Egyptians
• Egyptians also used
levers to move water
from rivers.
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.
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 wouldn’t be able
to lift as much water.
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.
Ancient Romans
• The catapults were
used to throw large
rocks at their
enemies.
• Catapults helped the
Romans defeat many
armies.
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.
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.
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.
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.
Work Cited
• Archimedes. Oct. 2006 <http://www.sciencetrek.net/archimedes
.htm>
• “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 <http://www.enchantedlearning.com/physics/machines/
Levers.shtml>
• Col, Jeananda. Zoom Inventors and Inventions. Enchanted
Learning. Oct. 2006 <http://www.enchantedlearning.com
/physics/machines/Levers.shtml>
• “Egyptian Pyramid.” Online Image. A Visit to the Pyramids… Oct.
2006. <http://members.cox.net/ancientsites/egypt/Pyramid_and_Sphinx.JPG>
Work Cited Continued
• History of Levers. Science Technology and Engineering. Oct. 2006
<http://www.enged.com.au/students/mecsys/mecsys17.html>
• Johnson, Jerry. Simple machines, work… Physical Science. Oct.
2006. <http://www.sirinet.net/~jgjohnso/simple.html>
• McKee, Jeffery. “Lever.” Online Image. Science of Evolution. Oct.
2006. <http://home.insight.rr.com/jkmckee/lever.jpg>
• “Roman Scissors.” Online Image. Oct. 2006
<http://www.petrie.ucl.ac.uk/detail/Images/72/UC36207.jpg>
• Simple Machines. 7 Oct. 2006. School for Champions. Oct. 2006
http://www.school-for-champions.com/science/machines.htm
• Third Class. Engine Mechanics. Oct. 2006.
<http://www.tpub.com/machines/1b.htm>
• Wheelbarrow. 7 Oct. 2006. Wikipedia. Oct. 2006.
<http://en.wikipedia.org/wiki/Wheelbarrow>