Question

A charged nonconducting rod, with a length of 3.83 m and a cross-sectional area of 5.69 cm2, lies along the positive side of an x axis with one end at the origin. The volume charge density ρ is charge per unit volume in coulombs per cubic meter. How many excess electrons are on the rod if ρ is (a) uniform, with a value of -3.76 µC/m3, and (b) nonuniform, with a value given by ρ = bx2, where b = -2.58 µC/m5?