566 PHENOMENA OF INDUCTION IN NON-LINEAR CONDUCTORS. 



585. Let us now suppose that a movable pole, of mass m, 

 moving uniformly in a straight line with the velocity #, and having 

 been in motion from an infinite time before the period in question, 

 is at the point A, at a distance c from the conducting shell X'X 

 (Fig. 124), and comes from a direction AjA such that it has not 

 yet traversed the shell. Let be the angle of this direction with 

 the perpendicular N to the shell. 



N 



Fig. 124. 



The angle a, which the magnetic trails B'jB' and BjB, relative 

 to the two successive positions A' and A of the pole make with N, 

 is defined by the triangle BB'C, which gives 



sma = 



u sin 

 TT~ 



