A uniform line charge that has a linear charge density λ equal to 3.5 nC/m is on the x axis between x = 0 and x = 5.0 m. What is its total charge? Find the electric field on the x axis at x = 6.0 m.

First, use the definition of λ to find the total charge of the line of charge. Integrate the line of change along the axis to find electric field. The line of charge is positive, and since the point p also lies directly on the x-axis, the field will point entirely in the +x direction.