An electron travels at a constant velocity at a distance \(d_{1}=4.0 \mathrm{~mm}\) above a large sheet of metal that carries a current of \(3 \mathrm{~A}\), and at a distance \(d_{2}=3.0 \mathrm{~mm}\) below a very long wire that carries a current \(0.5 \mathrm{~A}\). The wire is parallel to the sheet, and both currents flow in the same direction. Compute the width of the metal sheet.