On planet Seeturn, the free fall acceleration is 9.800 N/kg 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 micro C (5.00*10-6) is thrown upward at a speed of 20.1 m/s, and it hits the ground after an interval of 4.10s. What is the potential difference between the starting point and the top point of the trajectory?

2 answers

E is uniform? then force is Eq, and is downward.

force gravity=9.8
force electric=5e-6*E
total acceleration down=totalforce/mass

at the top, vfinal=zero
vf=vi+at where t=2.05sec
you know vi, t, solve for a. With that a, set it equal to totalforce/mass
and solve for E. Voltage=E*height achieved.
vf^2=vi^2+2ad, now solve for d, knowing E just found.
voltage difference is E*d
What is the final answer going to be and where did you get that t is 2.05 seconds