A bullet is fired from a gun with an initial horizontal velocity of 425 m/sec. It passes through a 2-kg block of wood, A, and becomes embedded in a second, 1.5-kg block of wood, B. The bullet causes Blocks A and B to begin moving to the right with velocities of 2 m/s and 3 m/s, respectively. The mass (g) of the bullet is most nearly: