the time of travel is
t = 8.82 s
the relation between the distance and the time is
given in the question that is
[tex]\sqrt[]{d}=t\times\sqrt[]{4.9}[/tex]
put t = 8.82
[tex]\begin{gathered} \sqrt[]{d}=8.82\times\sqrt[]{4.9} \\ \\ \end{gathered}[/tex]
square both side,
[tex]d=8.82^2\times4.9[/tex][tex]d=381.18[/tex]
so the height is 381.18 m
