A conducting bar of length l and mass m rests at the left end of the two

Question:

A conducting bar of length l and mass m rests at the left end of the two frictionless rails of length d in FIGURE P29.75. A uniform magnetic field of strength B points upward.

FIGURE P29.75

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. Find an expression for the bar€™s speed as it leaves the rails at the right end.