1. The problem statement, all variables and given/known data A sphere of radius 0.2 cm is fired straight up with speed v0. What is its speed when it hits the ground? (Include quadratic air resistance but ignore linear air resistance.) 2. Relevant equations Quadratic air resistance: FR = cv2 c = 0.5CpA = 4.05 x 10-6 3. The attempt at a solution I figured as the sphere rises, its velocity can be modeled as v = v0 - gt - cv2t/m. As it falls, velocity can be modeled as v = gt - cv2t/m. Other than that, I'm not really sure where to go.