A bare helium nucleus has two positive charges and a mass of 6.64 x 10-27 kg. (a) Calculate its kinetic energy in joules at 2.60% of the speed of light. J (b) What is this in electron volts? ev (c) What voltage would be needed to obtain this energy? V Additional Materials Reading Submit Answer 1 Points] DETAILS OSCOLPHYS2016 19.2.WA.019.TUTORIAL. Two parallel conducting plates are separated by a distance d = 12.2 cm. Plate B, which is at a higher potential has a value of 620 V. The potential at x = 7.50 cm from the plate B is 60.9 V. See diagram below. (a) What is the potential of plate A? (b) What is the direction of the electric field lines between the plates? O toward the left O toward the right O upward O downward Additional Materials Reading