$\left(g=10\,m / s ^2\right)$
From question, Horizontal velocity (initial),
\(u_x=\frac{40}{2}=20\,m / s\)
Vertical velocity (initial), \(50=u_y t+\frac{1}{2} g t^2\)
\(\Rightarrow u_y \times 2+\frac{1}{2}(-10) \times 4\)
\(\text { or, } 50=2 u_y-20\)
\(\text { or, } u_y=\frac{70}{2}=35\,m / s\)
\(\therefore \tan \theta=\frac{u_y}{u_x}=\frac{35}{20}=\frac{7}{4}\)
\(\Rightarrow \text { Angle } \theta=\tan ^{-1} \frac{7}{4}\)