The mysterious Planet Y has an upward uniform electric field and free-fall acceleration of exactly 9.80m/s^2. While on Planet Y, my brother tosses a 2.00-kg ball upwards from the surface and the ball strikes the ground 4.10s later. Given that the ball has a charge of -5.00 micro-coulomb and an upward speed of 20.1m/s, determine the potential difference between the ground and the top of the ball's trajectory