So this is dealing with the conservation of energy. So you set kinetic energy equal to potential energy, so it looks like this:
1/2mv^2=mgh. The m's cancel out, so it is 1/2v^2=gh.
To find out what the height h is, divide g on both sides, so...
h=0.5v^2/g. v=22m/s, g=9.81m/s^2, so h=(0.5)(22^2)/(9.81)=24.67m
