SIMPLE MACHINES TOPIC: THE LEVER!! Item: THE CATAPULT

DEFINITION Catapults are machines that converts POTENTIAL ENERGY into KINETIC ENERGY! Comes from the Greek word “Katapultos,” meaning “shield crusher” Catapults are also know as siege machines. Catapults can launch things a fair distance -- 500 to 1,000 feet (150 to 300 meters) is common

The Onager The Ballista The Trebuchet TYPES OF CATAPULT… The Onager The Ballista The Trebuchet

CATAPULTS: TYPES OF LEVER There are three types of levers. In a type 1 lever, the fulcrum is in the center of the lever, the load is at one end, and the effort is on the other end. In a type 2, the fulcrum is at one end, the load is in the middle, and the effort is on the other end. In a type 3, the fulcrum is at one end, the load is on the other, and the effort is in the middle. Catapults vary in the type of lever used and how the effort is applied. The throwing arm of the catapult is the lever, the fulcrum is where the arm attaches to the catapult, and the load is what the catapult is throwing. Catapults normally use type 1 or 3 levers

FUNCTION 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 There are many different types of catapult so they very in function and use. One of which called the Onager, work by storing tension either in twisted ropes or in a flexed piece of wood (in the same way an archery bow does, but on a larger scale).

HISTORY 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 By 330 BC two distinct types of catapults emerged One fired javelins (spears) called a Euthytonon The other was the stone throwing Palintonon

HOW IT WAS USED… During the Medieval period the catapult was used mostly against nobles who build great castles to protect themselves. There was no way to attack the nobles without getting through the walls first so they built the catapults to primarily attack from a distance and hurl projectiles over the wall. But slowly the catapult evolved into a more destructive type of siege machine (as if it wasn’t destructive enough), the catapult changed form and took the form of an arrow but much bigger. So thus the ballista was born to hurl projectile like arrows, spears and other sharp pointy objects. Unlike the earlier catapults the ballista was different in that it was more accurate.

CHANGE OVER TIME… The Beginnings of the Catapult is with the Greek Gastrophetes (Belly Bow) This was a bow that was laid out horizontal and braced up against the belly. This way the user could use both hands to draw back the string. It was more powerful than the regular bow. These Belly Bows got larger and more powerful and eventually they were taken off the belly and placed on a stand (This allowed them to get even larger. This new arrangement was called the Oxybeles. If you consider a catapult to be a siege weapon that stands along and is not hand-held then the Oxybeles is the first of this type. The Ballista - A fundamental change came about in the development of Catapults with the Ballista. Up until this point all of the typical catapult like weapons used the bending of wood as their source of power. The ballista used Torsion in the form of twisted ropes. This twisted rope torsion power was much stronger than the bending of wood and the ballista got much bigger and much more powerful. Even though the ballista used torsion for its power it still looked much like a crossbow in that it had two arms. This configuration changed significantly and other types of siege engine configurations came into use.

CHANGE OVER TIME CONTINUED… The Mangonel - When we think of a catapult this is often what we think of. Twisted ropes were attached to an arm with a bucket at the end. When the twisted ropes were released the arm shot forward and came to a stop against a crossbar. This would shoot whatever was in the bucket. The Onager - This is an interesting variation on the Mangonel in that instead of a bucket it had a rope and sling.

THE TREBUCHET The Trebuchet - Often considered to be the height of Siege Engine making because its simplicity allowed tremendously large ones to be made. It used gravity as its form of energy. 

PRESENT We do not hurl projectiles at castles anymore, but we do build them to have fun. Catapults as siege weapons became ineffective in 885-886 AD rendered useless by new defense technology, but they still continues to be used in military operations. Today however the most common use is to launch planes into the air.

The End By: FUAD MUHIT Sources: http://www.stormthecastle.com/catapult/development-timeline-of-the-catapult.htm http://science.howstuffworks.com/transport/engines-equipment/question127.htm https://sites.google.com/site/physicsofcatapults/home/modern-day-catapults The End

BIBLIOGRAPHY Website Title: HowStuffWorks https://sites.google.com/site/physicsofcatapults/home/modern-day-catapults Website Title: Modern Day Catapults - Physics of Catapults Article Title: Modern Day Catapults - Physics of Catapults http://science.howstuffworks.com/transport/engines-equipment/question127.htm Website Title: HowStuffWorks Publisher: HowStuffWorks.com http://www.stormthecastle.com/catapult/development-timeline-of-the-catapult.htm Website Title: Timeline and development of the catapult Article Title: Timeline and development of the catapult