Answer
$a = 28,000~g$
Work Step by Step
We can find the average acceleration:
$v_f^2 = v_0^2+2ad$
$a = \frac{v_f^2 - v_0^2}{2d}$
$a = \frac{(11,000~m/s)^2 - 0}{(2)(220~m)}$
$a = 2.75\times 10^5~m/s^2$
$a = (2.75\times 10^5~m/s^2)(\frac{1~g}{9.8~m/s^2})$
$a = 28,000~g$
