posted by Andrew .
A bullet moving at a speed of 154 m/s passes through a plank of wood. After passing through the plank, its speed is 149 m/s. Another bullet, of the same mass and size but moving at 91 m/s, passes through an identical plank. What will this second bullet's speed be after passing through the plank? Assume that the resistance offered by the plank is independent of the speed of the bullet.