Answer
The wall is $~~25.5~m~~$ high.
Work Step by Step
In part (a), we found that $v_{y0} = 29.4~m/s$
We can find the height of the wall:
$y = y_0+v_{y0}~t+\frac{1}{2}a_y~t^2$
$y = (1.00~m)+(29.4~m/s)~(1.00~s)+\frac{1}{2}(-9.8~m/s^2)~(1.00~s)^2$
$y = 25.5~m$
The wall is $~~25.5~m~~$ high.
