Two identical point charges, each of - 6.0 nC are held fixed on the x-axis, one at x= -3.0 cm, y =0 and the other at x = +3.0 cm, y= 0. In what follows, the electric potential is taken to be zero at infinity.

1. Calculate the electric potential VA at location A of coordinates x = 0, y= +4.0 cm, and the electric potential VB at location B of coordinates x = 0, y = 0 (the origin).

2. proton is released from rest at location A and immediately starts moving along the y axis towards location B. Use conservation of energy to calculate the speed of the proton when it reaches location B.