In: Physics
A rectangular loop is made by a metal bar that slides down a set of parallel rails of negligible resistance in a vertical gravitational field g. The rails are connected together by a third rail of negligible resistance The resulting loop is in a uniform, vertical magnetic field B. First assume there is no friction between the bar and the rails. (a) Does the bar acquire a constant velocity and if so what is it? (b) Now take the coefficient of kinetic friction between the bar and the rails to be µk. In this case does the wire acquire a constant velocity and if so what is it? (c) Show how your answers in (a) and (b) are, or are not, consistent with the principle of the conservation of energy. (c) If the direction of B is reversed, do your answers in (a) or (b) change? Explain