A bullet is fired through a board, 14.0 cm thick, with its l…

A bullet is fired through a board, 14.0 cm thick, with its line of motion perpendicular to the face of the board. If it enters with a speed of 450 m/s and emerges with a speed of 220 m/s, what is the bullet’s acceleration (in m/s2) as it passes through the board? Conversion: 100cm=1m