Answer: Approximately 302 m/s^2
================================================
Work Shown:
s = starting velocity = 0
f = final velocity = 46
d = distance = 3.5
a = acceleration = unknown (we're solving for this)
[tex]f^2 = s^2 + 2a*d \ \ \text{ ..... one of the kinematics equations}\\\\46^2 = 0^2 + 2a*3.5\\\\2116 = 7a\\\\7a = 2116\\\\a = \frac{2116}{7}\\\\a \approx 302.28571\\\\a \approx 302[/tex]
The acceleration to three sig figs is roughly 302 m/s^2
The acceleration is so large because the ball's final velocity is incredibly fast in such a short amount of time.