I recently did an expirement for my physics class in which we used a projectile launcher to fire a ball across a distance, where it would hit a piece of carbon paper. I've been asked to solve for the initial velocity, (Vi), and the only known information is: Vertical Acceleration = -9.81 m/s^2 Horizontal Displacement = 3.885m Delta Y (Height Ball was launched above the ground) = 1.015m Theta = 9 degrees I'm not asking anyone to solve this for me, but I'm really stuck. I was wondering if anyone could tell me the steps I must do, or even better, an equation that I could use to solve this. Any help is greatly appreciated. Thank you.