$\begin{array}{l}
W=W_{t \max }=m g h_{\max } \\
W^{\prime}=W_{d}^{\prime}+W_{t}^{\prime}=2 W_{t}^{\prime}+W_{t}^{\prime}=3 W_{t}^{\prime}=3 m g h^{\prime} \\
W=W^{\prime} \\
m g h_{\max }=3 m g h^{\prime} \\
\Rightarrow h^{\prime}=\dfrac{h_{\max }}{3}=\dfrac{3,6}{3}=1,2 m
\end{array}$