A bullet fired straight through a board \(0.10 \mathrm{~m}\) thick strikes the board with a speed of \(480 \mathrm{~m} / \mathrm{s}\), has constant acceleration through the board, and emerges with a speed of \(320 \mathrm{~m} / \mathrm{s}\).

(a) What is the component of the acceleration in the direction of the bullet's motion?

(b) What is the time interval between the instant the bullet strikes the front face of the board and the instant it exits the back face?

(c) Assuming the average acceleration you calculated in part \(a\), what minimum thickness must the board have in order to stop the bullet?