$(1)$
\[A_1V_1=A_2V_2=Q\]
\begin{align}
V_1=\frac{Q}{A_1}=\frac{4Q}{\pi d_1^2}&=\frac{4\times0.2}{\pi\times0.3^2}\\
&=2.8294\\
&=2.83\,\rm{m/s}
\end{align}
\begin{align}
V_2=\frac{4Q}{\pi d_2^2}&=\frac{4\times0.2}{\pi\times0.15^2}\\
&=11.318\\
&=11.32\,\rm{m/s}\end{align}
$(2)$
\[
\frac{p_1}{\rho}+\frac{V_1^2}{2}=\frac{p_2}{\rho}+\frac{v_2^2}{2}
\]
\begin{align}
p_2&=\frac{\rho}{2}(V_1^2-V_2^2)+p_1\\
&=\frac{1000}{2}(2.829^2-11.318^2)+300\times10^3\\
&=239953\\
&=240.0\,\rm{kpa}
\end{align}
$(3)$
\begin{align}F_x&=\rho QV_1-\rho QV_2\cos60^\circ +p_1\frac{\pi}{4}d_1^2-p_2\frac{\pi}{4}d_2^2\cos60^\circ \\
&=1000\times0.2\times(2.8294-11.318\cos60^\circ )\\
&+(300\times0.3^2-239.95\times0.15^2\times\cos60^\circ )\times\frac{\pi}{4}\times1000\\
&=18520\\
&=18.52\,\rm{kN}
\end{align}
\begin{align}F_y&=0-(-\rho QV_2\sin60^\circ )+P^2\frac{\pi}{4}d_2^2\sin60^\circ \\
&=1000\times0.2\times11.318\sin60^\circ \\
&+239.95\times1000\times\frac{\pi}{4}\times0.15^2\sin60^\circ \\
&=5632.5\\
&=5.63\,\rm{kN}
\end{align}
$(4)$
\begin{align}F=\sqrt{F_x^2+F_y^2}&=\sqrt{18.52^2+5.633^2}\\
&=19.36\rm{kN}
\end{align}
\begin{align}\beta=\tan^{-1}\frac{F_y}{F_x}&=\tan^{-1}\frac{5.633}{18.52}\\
&=16.92^\circ
\end{align}