I'm currently working on an engineering project for my high school engineering course, and the knowledge of physics I should have for this project is more than I actually know. I want to build a catapult that can shoot a tennis ball at an 8” target on the ground from 30 feet away. I want to take into account wind resistance in the building of my catapult, but I’m having trouble finding the right equation for drag forces on arcs. Is there anyone who can help me with this? I’m working on my general blueprints for the project, so I’ll be able to give you exact dimensions and measurements before long, but as of now I don’t have any. I can tell you that there will be no angle on the plain of the catapult and the target, so it’ll be level, and I can vary the weight on the arm of my catapult launching the tennis ball. Does anyone know what kind of equation I should be using?