\(S_y=u_y T+\frac{1}{2} g_y T^2\)
\(-40=4 \sin 30 T-\frac{1}{2} g T^2\)
\(-40=20 \times \frac{1}{2} T-5 T^2\)
\(-8=2 T-T^2\)
\(T^2-2 T-8=0\)
\(T^2-4 T+2 T-8=0\)
\(T=-2,4\)
\(R=u \cos \theta T=20 \times \frac{\sqrt{3}}{2} \times 4\)
\(R=40 \sqrt{3} \,m\)