The rail gun. The simple configuration in Figure Q20.12 provides a means for launching p...

The rail gun. The simple configuration in Figure Q20.12 provides a means for launching projectiles, as long as the projectile can conduct electricity. Two copper rails are connected to a battery such that the current flows as indicated in the figure when a conducting rod is laid across the rails. What will happen to the conducting rod? If it begins to move, in what direction does it go? Consider (a) the direction of the magnetic field produced in the vicinity of the rod by the currents in the rails and rod and (b) the direction of the current in the rod. How could one make the rod move in the opposite direction?