Answer
$$\theta_0\mathrm{}=8.94 \mathrm{rev}
$$
Work Step by Step
Datum at initial position.
$$
\begin{gathered}
T_1+V_1=T_2+V_2 \\
0+2\left[\frac{1}{2}(0.7) \theta_0^2\right]+0=0+150(9.81)(1.5) \\
\theta_0=56.15 \mathrm{rad}=8.94 \mathrm{rev} .
\end{gathered}
$$
