1. The problem statement, all variables and given/known data 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 20.1 m/s. 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? 2. Relevant equations Work = (q)(E)(delta x) q=charge, E= electric field delta V = (delta PE)/q V=electric potential difference 3. The attempt at a solution I pretty sure we'd have to use the conservation of energy to determine the solution and the a physics 1 kinematic equation. I know the background of the question but I just can't figure out how the electric field comes into play for the question. Can someone please help me understand this question? Thanks a lot in advance for your help.