What's going on extremely close to the stick.) what do things y look like near the point you found in part (a)? 246 right triangle φ ** the right triangle shown in fig. 2.48 with vertex p at the origin has base b, altitude a, and uniform density of surface charge σ. determine the potential at the vertex p. first find the contribution of the vertical strip of width dx at x. show that the potential at p can be written as φp = (σ b/4π60) in[ (1 + sin θ)/ cos θ]. 2.47 a square and a disk p use the result from exercise 2.46 to answer the following ques- tion. if a square with surface charge density σ and side s has the same potential at its center as a disk with the same surface charge density and diameter d, what must be the ratio s/d? is your answer reasonable? fiaure 2.48