You have a baseball with mass 144 g. By rubbing the ball on your hair, you give it a negative charge of 8,000 nC. You go outside while a thundercloud is passing overhead and throw the ball straight up with an initial speed of 10.6 m/s. Using sophisticated timing equipment, you notice that the time it takes to go up and return to its original position is 0.25 percent faster than if there is no charge on the baseball. What is the electric field near the ground ?