Abullet of mass m is fired through a wooden board of mass m and length l free to pivot about a fixed axis through its center. the bullet's initial velocity is v0 and its final velocity is 0.69 v0. the bullet moves in a straight line (perpendicular to the pivot axis) and hits the board at a point midway between the pivot and the end of the board. find the final angular velocity of the board about its center. express your answer in terms of the given quantities.