## CatapultMade by Cameron Geiser, Joe Brittenham, and maggie reichler

Base design for Catapult.

This is the inspiration we used for the catapult. We tweaked the image a bit to make it match our connector types better.

One of our many changes is we used duct tape for the cross bar. We also taped the bungee cord to the PVC pipe launch arm to make the arm more powerful. The changes we made to the original design is instead of having the 45° PVC's we made them into 90° PVC's. The reason is we couldn't find PVC pipe at that angle so we changed it to 90°. We couldn't find full 90° corners so we improvised and used a corner that was grated and added the grated corner to it.

Everything we needed for this was:

1. bungee cord

2. 24Ft. 7In. of PVC pipe

3. 14 connectors (8 90°, 7 T's)

4. Plastic cup

5. duct tape

We had an additional \$5.00 shopping cart from Home Depot. In our shopping cart, we had four 90° angle connectors.

During the very first launch we did, the ball was not going very far. We decided to switch the bungee cord out for a smaller one and tape it down. This made the pull much stronger, making the ball go much farther.

This is our data. Our testable question was: If we pull the leaver all the way down to the ground, the ball will go farther than if we pull the leaver only half way to the ground. The first set of data is the leaver being pulled all the way down, the second set is the leaver being pulled only half way.

Vertex form equation
trajectory graph

Our catapult does lance consistently. Every time it lances, it lands around 61-17 feet.

We could make the lance more consistence by moving the tape measure to where the back of the catapult is, opposed to where the front of if is.

To make our launch go farther, we made the bungee cord much tighter, and added a blocker underneath it so it can not slide down. To make it go even farther, we could make the bungee tighter, or move the blocker up.

To hit a bull's eye every time, we would need to put our target about 16 feet away from the catapult.

Our projectile hits the ground around 16 feet according to the equation we found.

The maximum height of the ball is six feet, and it occurs at seven feet from the catapult.

This is how high the ball is at six feet.

We could make the maximum height higher by making the arm more powerful. This would make the maximum height higher because the ball would have more power and more force, making it able to go farther and higher. The effect this would have on the projectile is the ball would go farther, because the arm has more power to fling it harder, farther, and higher.

Overall, our catapult was built very nicely, and was one of the more intricate looking catapults. We are proud of our final product.