A rail gun uses electromagnetic forces to accelerate a projectile to very high velocities. The basic mechanism of acceleration is relatively simple and can be illustrated in the following example. A metal rod of mass 50.0g and electrical resistance 0.500Ω rests on parallel horizontal rails that have negligible electric resistance. The rails are a distance L = 5.00cm apart. The rails are also connected to a voltage source providing a voltage of V = 5.00V. The rod is placed in a vertical magnetic field. The rod begins to slide when the field reaches the value B = 0.490T. Assume that the rod has a slightly flattened bottom so that it slides instead of rolling. Use 9.80m/s² for the magnitude of the acceleration due to gravity. Find μs, the coefficient of static friction between the rod and the rails. Give your answer numerically.