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 50.0 and electrical resistance 0.100 rests on parallel horizontal rails that have negligible electric resistance. The rails are a distance = 5.00 apart. The rails are also connected to a voltage source providing a voltage of = 5.00 .
The rod is placed in a vertical magnetic field. The rod begins to slide when the field reaches the value = 9.80×10-2 . Assume that the rod has a slightly flattened bottom so that it slides instead of rolling. Use 9.80 for the magnitude of the acceleration due to gravity.
Find, the coefficient of static friction between the rod and the rails.