A small projectile launcher is mounted on a flatcar at a height \(h\) above the ground. In Experiment 1, the flatcar is stationary, and the launcher fires a ball horizontally with speed \(v\) relative to the car. The ball travels a horizontal distance \(D_1\) relative to the ground before hitting the floor. In Experiment 2, the flatcar moves at a constant speed \(v\) in the same direction the ball is launched. The launcher again fires the ball horizontally with speed \(v\) relative to the car, and the ball travels a horizontal distance \(D_2\) relative to the ground before hitting the floor. What is the ratio \(D_2 / D_1\)?