science of catapults

The ABMAMACAW Catapult Catapults were first made to hurdle cats (on a more serious note). There are many different types of catapults, such as the mangonel catapult. The mangonel catapult which our catapult is based on was created in 400 B.C. by the Romans. The mangonel was created like the Greek ballista but was smaller and mobile. Our catapult was based on some aspects of the mangonel. In the following I will talk about the process and materials used to make it and the science of the catapult.
Some of the materials we used are:
Wood- for the structure of the catapult
Bungee Cords- to give the arm a bounce so when the ball is released it would go far
Spray Paint- to give a base of color to the catapult
Paint- to do splatter paint and give the catapult personality
Rubber Bands- to give the arm a bounce so when the ball is released it would go far
Lacrosse Stick- is used as the top of the arm where the ball will sit until launched
Pipe- gives the arm height so that the ball will go far
Duct Tape- to strengthen the attachment between the pipe and the lacrosse stick

First we drew out a lay out of what we thought the catapult was going to look like. We drew it in both a front view and bird’s eye view. Then we wrote out how long we thought the pieces of wood would be. Next we went to Carmen’s Grandpas’ shop where we started the base of the catapult. After that we added the center piece which would be where the arm hits to stop at an 80° angle. Next we added the arm and tested it out. Finally we painted it and and topped that off with some splatter paint.
Our catapult stores energy in the bungee cords at the bottom. When the ball is fired the potential energy in the bungees are converted into kinetic energy. The force of the bungee cords causes the bottom of the arm to fly back and the front of the arm to fly forward. The kinetic energy travels through the arm to the top of the lacrosse stick and into the ball. The