A device called a railgun uses the magnetic force on currents to launch projectiles at very high speeds. An idealized model of a railgun is illustrated in the following figure. A 1.2 volt power supply is connected to the two conducting rails. A segment of copper wire, in a region of uniform magnetic field, freely slides on the rails. The wire has a 0.85 mΩ resistance and a mass of 5.0 g. Ignoring the resistance of the rails, when the power supply is connected a) what is the current in the circuit? b) what are the magnitude and direction of the force on the wire? c) what will be the wire's speed after it has slid a distance of 1.0 mm?
