Answer
His pitching speed is 27.7 m/s
Work Step by Step
We can find the flight time of the ball;
$y = \frac{1}{2}gt^2$
$t = \sqrt{\frac{2y}{g}}$
$t = \sqrt{\frac{(2)(4.0~m)}{9.80~m/s^2}}$
$t = 0.904~s$
We can find the ball's initial speed;
$v_x = \frac{x}{t} = \frac{25~m}{0.904~s}$
$v_x = 27.7~m/s$
His pitching speed is 27.7 m/s
