An infinitely long, uniform rod of mass μ per unit length is situated on the z axis,
(a)Calculate the gravitational force F on a point mass m at a distance rho from the z axis. (The gravitational force between two point masses is given in Problem 4.21.)
(b) Rewrite F in terms of the rectangular coordinates (x, y, z) of the point and verify that Vx F-0.
(e) Show that V x F-0 using the expression for Vx F in cylindrical polar coordinates given inside the back cover.
(d) Find the corresponding potential energy U.