Solve the all parts of given problem:
Problem: Two 2.6cm -diameter disks face each other, 3.0mm apart. They are charged to ±20nC.
Part A: What is the electric field between the disks?
Part B: A proton is shot from the negative disk toward the positive disk. What launch speed must the proton have to just barely reach the positive disk?
I need help to find what launch speed must the proton have to just barely reach the positive disk.