Two long, straight, parallel wires separated by a distance \(d\) carry currents \(I_1\) and \(I_2\) in the same direction, resulting in an attractive magnetic force per unit length of magnitude \(\dfrac{F_0}{L}\). The current in the first wire is changed to \(3I_1\), the current in the second wire is changed to \(\dfrac{1}{2}I_2\), and the distance between the wires is increased to \(2d\). What is the new magnetic force per unit length between the wires?