1. The problem statement, all variables and given/known data You need to calculate the electric potential for a thin, long tube with a uniform surface charge density (σ). This tube has a length L and a radius R. Find the electric potential along the tube axis for points outside the tube. 2. Relevant equations 3. The attempt at a solution I am having trouble getting this problem. If I am understanding it correctly, we are supposed to calculated V either above or below the tube, as long as it is along the tube's axis. I am not sure how to set up my problem. Should I set the origin of my axes between L/2 and -L/2? I am not sure where to start. Thanks.