1. The problem statement, all variables and given/known data If you want to use a catapult to throw rocks, and the max range is 0.67 km, what initial speed must the rocks have as they leave the catapult? 2. Relevant equations v=Δr/Δt 3. The attempt at a solution I sketched a graph of the projectile trajectory with the desired range on the x-axis. I also converted 0.67 km to 670 m. I concluded that acceleration would be -9.8 m/s. I couldn't go any further since I feel like I am not given enough information to work with.