## CatapultBy: Josh Theeke, Brooke Burste, Becca Rocco, and Molly Clausen

### Inspirations

These two designs were our main inspiration for our catapult. From the left we took the base design-except for the middle piece where the arm connects and the idea of having something in the middle to stop the arm from going a full 180 degrees. From the left, we took the idea of having a frame around part of our structure to strengthen it.

### Materials

We used: six corner pieces, three t-pieces, ≈11.5 feet of pvc, and one bungee cord.

### DEsign log

One revision that we made after our initial launch was we figured out that we needed to have a constant spot where we pulled down the arm to. (Height of an iPhone 6)

• Is your catapult launching consistently every time? Yes, it did. Our launches were around 18 to 19 feet every time.
• What can you change to make the launch consistent every time? Have a structured distance and level to pull our arm down.
• What revisions can you make to get your catapult to launch farther? We can pull the arm down further, but that would mess up accuracy.
• Where do you need to place your target to hit a bullseye every time? We need to place it at 18.5 feet.

### y=a (x-111.63)^2+75

• When does your projectile hit the ground according to the equation you found? It should hit at around 223 inches or 18.5 feet.
• What is the max height of the ball? Where did the max height occur? The max height is 111.62 or 9.3 feet. This occurred at 111 feet.
• What is the height of the ball when it has traveled 6 feet? About 60 inches or 5 feet.
• How could you make the max height higher and what effect would it have on the projectile? Pull the arm back farther, but this would mess with the accuracy and the distance the ball travels.