11. A naughty student throws a water balloon straight down with a speed of 2.5 m/s from a window 13 m above the ground. When will the balloon hit the head of an innocent, 2.0-m-tall passerby? What is its speed when it hits? 12. An electron with speed of 104 m/s enters a "forbidden" region where an electric force tries to push it back along its original path with a constant acceleration of 107 m/s2 . How far will the electron go into the "forbidden" region if the reference point is the start of the "forbidden" region? How much time will the electron be in that region?