The catapult is an invention made by the ruler of Syracuse, Dionysius the Elder. It was made in 400 BC, and was used as a weapon for war. It was used in historical battles until about the 14th century. When the 14th century came around people had invented gun powder and they could make guns and cannons that could fire faster and stronger than a catapult. The catapult became obsolete shortly after. There were also other people in history that had created a variant of the catapult. The Romans made a catapult called the ballista. The ballista was different because it was made like a giant crossbow. It would fire giant arrows and stakes. There was also the trebuchet made in 300 BC by the Chinese. A trebuchet uses a counter weight and gravity to fire the weapon while the other two use elastic force.

Day 1 : I wasn’t there for the first day since I was writing a test.

Day 2: we created a design for our catapult and figured out what materials we would need.

Day 3: we made the base for the catapult and redesigned our plans for the actual mechanism.

Day 4: we finished the top of our catapult and mended a few errors, like when we fired the top of the catapult broke off.

Our catapult was powered by elastic force, with the elastics being attached to both the base of the catapult and the throwing arm. When someone pushes down on the throwing arm, it stretches the elastics creating potential elastic energy. When the arm is launched, a lot of the stored energy is lost with the acceleration, leaving it with no force after the projectile leaves the holder. The frame of the catapult uses triangles because it is one of the strongest shapes and let’s the force be distributed throughout the machine better.