1. The problem statement, all variables and given/known data mass=m length=l initialspeed=v0 magneticfield=B Resistor=R 2. Relevant equations A metal rod of mass m and length l slides on two parallell frictionless rails. A uniform magnetic field is directed perpendicular to the plane of the rails. There is no external agent applying a force to the rod. Show that v(t) = v0e^t/T where T = mR/(Bl)² 3. The attempt at a solution I dont know where to start. Shall I construct a differentialequation including dt and dA? If not the solution I would be greatful for some hints.