A conducting bar of length I and mass m rests at the left end of the two frictionless rails of length d in the figure below. A uniform magnetic field of strength B points upward. a) In which direction, into or out of the page, will a current through the conducting bar cause the bar to experience a force to the right? b) Assuming a current I in the direction you found in part (a), find an expression for the bar's speed as it leaves the rails at the right end.

A conducting bar of length I and mass m rests at the left end of the two frictionless rails of length d in the figure below. A uniform magnetic field of strength B points upward. a) In which direction, into or out of the page, will a current through the conducting bar cause the bar to experience a force to the right? b) Assuming a current I in the direction you found in part (a), find an expression for the bar's speed as it leaves the rails at the right end.