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 Figure P24.48. A \(1.2 \mathrm{~V}\) power supply is connected to two conducting rails. A segment of copper wire, in a region of uniform magnetic field, slides freely on the rails. The wire has a \(0.85 \mathrm{~m} \Omega\) resistance and a mass of \(5.0 \mathrm{~g}\). Ignore the resistance of the rails. When the power supply is switched on,

a. What is the current?

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 \(6.0 \mathrm{~cm}\) ?

1.2V 15 cm x X B = 0.80 T Kation FIGURE P24.48