A particle with charge 3.20×10−19 C is placed on the x axis in a region where the electric potential due to other charges increases in the +x direction but does not change in the y or z direction.

Part A:
The particle, initially at rest, is acted upon only by the electric force and moves from point a to point b along the x axis, increasing its kinetic energy by 8.00×10−19 J . In what direction and through what potential difference Vb−Va does the particle move?

The particle moves to the left through a potential difference of Vb−Va= 2.50 V .
The particle moves to the left through a potential difference of Vb−Va= -2.50 V
The particle moves to the right through a potential difference of Vb−Va= 2.50 V .
The particle moves to the right through a potential difference of Vb−Va= -2.50 V .
The particle moves to the left through a potential difference of Vb−Va= 25.0 V .
The particle moves to the right through a potential difference of Vb−Va= -25.0 V .

Part B:
If the particle moves from point b to point c in the y direction, what is the change in its potential energy, Uc−Ub.

+ 8.00×10−19 J
− 8.00×10−19 J
0