Halliday, Resnick & Walker — Magnetic Fields: Problem 30

30 A long, rigid conductor, lying along an x axis, carries a current of 7.0 A in the negative x direction. A magnetic field \(\vec{B}\) is present, given by \(\vec{B} = 3.0\hat{i} + 8.0x^2\hat{j}\), with \(x\) in meters and \(\vec{B}\) in milliteslas. Find, in unit-vector notation, the force on the 2.0 m segment of the conductor that lies between \(x = 1.0 \text{ m}\) and \(x = 3.0 \text{ m}\).