On planet Tehar, the acceleration of gravity is the same as that onEarth but there is also a strong downward electric field with thefield being uniform close to the planet's surface. A 1.98 kg ball having a charge of 5.05 µC is thrown upward at a speed of 20.1m/s and it hits the ground after an interval of 4.10 s. What is the potential difference between the starting point and the top point of the trajectory?