On planet Tehar, the free-fall acceleration is the same as that on Earth but there is also a strong downward electric field that is uniform close to the planet's surface. A 2.00 kg ball having a charge of 5.00 µC is thrown upward at a speed of 29.2 m/s and it hits the ground after an interval of 4.40 s. What is the potential difference between the starting point and the top point of the trajectory?