(13%) Problem 7: A long straight metallic pipe has radius a and surface charge density o. A point located a distance 3a from the CO axis of the pipe has been designated as the zero of potential energy. CO A 20% Part (a) Due to the cylindrical symmetry, the electric field may be expressed as E = E,f where f is perpendicular to the axis of the pipe. Enter an expression for the radial component of the electric field, Er , that is valid outside of the pipe, where r > a. Er = 1 Grade Summary Deductions 0% Potential 100% Ho 7 8 9 HOME Submissions 4 5 6 Attempts remaining: 999 (0 % per attempt) a In(2r/3a) 3 detailed view In(2r/a) In(3r/a) In(r/2a) 0 END In(r/3a) Z VO BACKSPACE DEL CLEAR Submit Hint Feedback I give up! Hints: 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback. A 20% Part (b) Due to the cylindrical symmetry, the electric field may be expressed as E = E,f where / is perpendicular to the axis of the pipe. Enter an expression for the radial component of the electric field, E, , that is valid outside of the pipe, where r a. Recall that a point located a distance 3a from the axis of the pipe has been designated as the zero of potential energy. A 20% Part (d) Enter an expression for the electric potential, V, that is valid inside of the pipe, where r