1. The problem statement, all variables and given/known data There is a thin rod of length L that carries a uniform charge per unit length [tex]\lambda[/tex]. Starting from the expression for the potential of a point charge, derive an expression for the electric potential V (y) at a distance y away from the centre of the rod on the axis (y) of the rod. Assume y > L/2. Use this result to derive the y-component of the electric field, Ey, along the axis of the rod, for y > L/2. 2. Relevant equations V(r) = Q/4[tex]\pi[/tex][tex]\epsilon[/tex]r [tex]\Delta[/tex]V = - [tex]\int[/tex]E[tex]\cdot[/tex]ds 3. The attempt at a solution I thought that the electric potential would be unchanged since the electric field is perpendicular to the displacement... Or is this acceptable because the wire is not infinite?