Make a catapult that shoots far, but not high. Have a part on it that will stop the ball on it from flying too far forward.
This was the inspiration for our catapult. This catapult looks a lot like ours, but still has many differences.
In our experiment what we did was:
1. Place our catapult on the ground and mark the point to where the catapult was pulled back to as 0,0. This was because the ball started where the catapult was pulled down too, which was 0,0, and we wanted to have a parabola.
2. We launched our catapult 4 times, and found the point where it stopped.
3. To find the vertex, we launched it by a wall so we could mark the point where it was highest and mark it.