Using a zero reference potential at infinity, determine the amount by which a point charge of 4 ×10–8 C alters the electric potential at a spot 1.2 m away when the charge is (a) positive and (b) negative.

Two identical point charges, each of 2.0 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.   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).  An electron 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 electron when it reaches location B.

A charge of uniform density (20 nC/m) is distributed along the x axis from the origin to the point x = 16.1 m. What is the electric potential (relative to zero at infinity) at a point, x = 83.2 m, on the x axis?

A +6 μC charge is distributed uniformly over a 12.6 m rod centered at the origin and oriented parallel to the x axis. Taking the potential to be zero at infinity, what is the electric potential at the position (22.1,0)m?