Two large, parallel, current-carrying plates are oriented horizontally and the vertical distance between them is \(5.0 \mathrm{~mm}\). The current per unit width in each plate is \(100 \mathrm{~A} / \mathrm{m}\), and both currents are in the positive \(x\) direction. Determine the magnitude and direction of the magnetic force per unit area exerted by the lower plate on the upper plate.