Halliday, Resnick & Walker — Magnetic Fields Due to Currents: Problem 11

11 In Fig. 29-29, five long parallel wires in an \(xy\) plane are separated by distance \(d = 50.0 \text{ cm}\). The currents into the page are \(i_1 = 2.00 \text{ A}\), \(i_3 = 0.250 \text{ A}\), \(i_4 = 6.00 \text{ A}\), and \(i_5 = 2.00 \text{ A}\); the current out of the page is \(i_2 = 4.00 \text{ A}\). What is the magnitude of the net force per unit length acting on wire 3 due to the currents in the other wires?