Catapults

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Catapults
Samuel Bradshaw
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Introduction What is a catapult?
A catapult is a machine that shoots objects into
the air. It was often used as a weapon - to shoot
large boulders at the enemy. Basically, its a
large lever.
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History of the Catapult

• Catapults were the first form of field artillery
  used by the Greeks.
• The word Catapult means shield piercer.
• The first catapults were based on the bow and
  arrow.
• They were called Ballista, and they shot spears.

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History of the Catapult

• It was difficult to construct, so the Romans
  developed the Mangonel.
• It is the type of catapult that we are most
  familiar with.
• The catapult was slowly replaced by gunpowder
  artillery during the 14th and 15th centuries.

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Trajectory / Launch Concepts

• Trajectory the path a projectile makes through
  space under the action of given forces such as
  thrust, wind, and gravity.

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A Simple Catapult
18.5 cm
16 cm
11 cm
21.5 cm
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Fantastic Factfile Machines
A Machine is a simple device used to make work
easier. There are six basic simple machines
An inclined plane is a slanted surface that
increases the distance, but decreases the work. A
ramp is an inclined plane.
A screw is an inclined plane wrapped around a
bar. A corkscrew is a type of screw.
A lever is a bar that pivots around a fulcrum. A
crowbar is a type of lever.
A wheel and axle is a cylindrical drum and wheel
mounted on the same axle.
A wedge is a movable inclined plane. The blade of
a knife is a wedge.
A pulley consists of a wheel and a rope or string
that is wrapped around it. Pulleys can
change direction of a force as well as increase
the mechanical advantage.
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What is Force?
A force is a push, pull, or lift.
Effort force - the force applied to a
machine Resistance force - the force that opposes
the effort force (weight) Efficiency- the
comparison of work output to work
input Mechanical advantage - the number of times
a machine multiplies the effort force
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Conclusion
A catapult is a machine that shoots objects into
the air. It was often used as a weapon. It is a
lever - one of the six types of
machines. Machines make work easier.
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The End