For problems 13 and 14, the ”x component of its velocity just before it strikes the ground is vf in the horizontal direction. The ”y component of its velocity just before it strikes the ground” is vf in the vertical direction. A ball is thrown horizontally from the top of a building 19 m high. The ball strikes the ground at a point 98.2 m from the base of the building. The acceleration of gravity is 9.8 m/s 2 . Find the time the ball is in motion.