c a t a p u l t s physics, background and history
DESCRIPTION
C A T A P U L T S Physics, Background and History. Definition. A machine that converts POTENTIAL ENERGY into mechanical motion or KINETIC ENERGY ” Comes from the Greek word “ Katapultos , ” meaning “ shield crusher ” AKA: Siege Engine or Siege Machine. The Invention. - PowerPoint PPT PresentationTRANSCRIPT
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C A T A P U L T SC A T A P U L T SPhysics, Background and
History
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Definition
A machine that converts POTENTIAL ENERGY into mechanical motion or KINETIC ENERGY”
Comes from the Greek word “Katapultos,” meaning “shield crusher”
AKA: Siege Engine or Siege Machine
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The Invention
The catapult, as we would recognize it today, was invented by the Greeks about 399 BC but various forms were found in central Asia much earlier than that
During the war with Carthage, Dionysius of Syracuse produced the Gastraphetes or “belly bow” catapult
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The Invention continued…
By 330 BC two distinct types of catapults emerged
One fired javelins (spears) called a Euthytonon
The other was the stone throwing Palintonon
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How was it used in Medieval times?
First we need to understand the society of the Middle Ages
Fear was rampant (AKA: Dark Ages) There was huge disparity between the
rich and poor (Feudalism) Castles were constructed to protect
nobles (& peasants but only during crisis)
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Castle construction
Moat Draw bridge Portcullis Guard tower/ Barbican Murder holes
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Portcullis
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Catapult AKA Siege Machine or Siege Engine
What is a siege? One army surrounds an enemy,
keeping help, goods and water from leaving or entering the castle
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Medieval warfare
Infantry (usually the poor) Archers (trained/ paid military) Battering Ram Psychological warfare Flaming shrubbery and brushDead, diseased bodies Heads of tortured victims
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Battering Ram
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A typical catapult has each of the following:
Arm Base Elastic Force Fulcrum
Catapult Structure & Design
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Most catapults were made of wood The elastic force provided by twisted
rope, springs, saplings The fulcrum is the point of support
for a lever- which in the case of a catapult is the arm
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Factors Affecting Distance
Mass of object being hurled Strength & flexibility of arm Mass of arm Length of the arm How far the arm is pulled back Angle of base or release (best angle?) Small transfer of energy into distortion
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Types of Catapults Roman design and others found
during the Medieval period
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Ballista
Roman Double
armed – like a bow
Shot large spears or javelins
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Mangonel or Onager
French “Engine of War” Typical catapult
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Trebuchet
French meaning “to stumble” Used a sling with the arm Extremely accurate Most advanced of all catapults
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Fixed Counterweight
Trebuchet
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Swinging or Hinged Counterweight Trebuchet