(3) A copper rod of length 0.85 In is lying on a frictionless table (see the drawing). Each end of the rod is attached to a fixed wire by an unstretched spring that has a spring constant of k = 75 N/m. A magnetic field with a strength of 0.16 T is oriented perpendicular to the surface of the table. (a) What must be the direction of the current in the copper rod that causes the springs to stretch? (b) If the current is 12 A, by how much does each spring stretch? Table (top view) Fixed wires O ._. C O O % line\" of paperiil'm):a : :3 E . ECopBer rod. '3, 0 O O O