A conducting bar rests over two metal rails that are connected to a battery. The entire con- figuration is placed in an external, uniform magnetic field. If a current is pumped through this circuit it will interact with the external magnetic field and cause the bar to slide. Bext L For this problem ignore friction and air resistance. The length of the bar is L = 1 [m], the magnetic field strength is B = 10 [T], and the current in the circuit is I = 103 [A]. a) Write down the magnetic force on the conducting bar. b) Show with a cross product that it must point to the right. c) What is the kinetic energy of a 1 [kg] bar that is traveling at v = 343 [m/s]? This is the speed of sound. d) How long does the rail need to be to get to this speed?