(Solved): In a large thunderstorm cloud, collisions between ice crystals moving upwards, and soft hail (call ...

In a large thunderstorm cloud, collisions between ice crystals moving upwards, and soft hail (called graupel) which is either stationary or moving downwards, creates a separation of charge. In such clouds there is a large negative charge near the middle/lower portion of the cloud, and this causes the ground to become positively charged. The electric field produced by this can be as large as 10,000 V/m. You have a baseball with mass $$143.4\mathrm{g}$$. By rubbing the ball on your hair, you give it a negative charge of 6,950 nC. You go outside while a thundercloud is passing overhead and throw the ball straight up with an initial speed of $$12.4\mathrm{m}/\mathrm{s}$$. 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?