Q1) A railgun uses the magnetic force on electric currents to launch projectiles at high speeds. The railgun shown in the figure has a 6 V power supply connected to two conducting rails. An 8-cm long piece of copper wire with a mass of 25 grams, and resistance of 0.86 m? slides freely on the rails in a uniform magnetic field of 0.93 T. The resistance of the rails is negligible.

X X X X X X X X X X X X 8 cm X X X X 6.0 V X X X X 0.93 T X X X X