A very long insulating cylindrical shell of radius 6.40 cm carries charge of linear density 8.90μC/m spread uniformly over its outer surface. What would a voltmeter read if it were connected between the surface of the cylinder and a point 4.00 cmabove the surface? λ=dq/dr V=k∫dq/r V=λk*ln([r+x]/r) V=(8.9e-6)*9e9*ln(.104/.064) V=3.89e4 The actual answer is 7.78e4 (twice my answer). I can't figure out whats wrong with my integral to make the answer half of what it should be. Thanks!