At the instant a cannon fires a ball horizontally, another is dropped from the same height. The stroboscopic images of the motion of two balls are shown in the diagram. The camera captured one frame every 0.1 s. (a) Explain how this diagram illustrates characteristics of projectile motion proposed by Galileo. (b) Use the diagram to determine the launch velocity of the projectile.

At the instant a cannon fires a ball horizontally, another is dropped from the same height. The stroboscopic images of the motion of two balls are shown in the diagram. The camera captured one frame every 0.1 s. (a) Explain how this diagram illustrates characteristics of projectile motion proposed by Galileo. (b) Use the diagram to determine the launch velocity of the projectile.