posted by Angelo .
A long, straight wire has a uniform linear charge density of 7.50X10^-4 C/m. A point charge q=15.0 microcoulombs is located 4.50 cm away from the wire. Find the magnitude of the force exerted by the charge q on the wire.
You will have to perform a Coulomb's- Law integration of the force due to individual line elements of length dx, each with charge 7.50X10^-4 dx.
The answer will depend upon which part of the wire the point charge is "below" . They probably expect you to assume that it is below the middle. That will make the integration easier since forces along the wire direction will cancel due to symmetry.