• # question_answer A projectile is projected from a level ground making an angle $\theta$ with the horizontal (x direction). The vertical (y) component of its velocity changes with its x co-ordinate according to the graph shown in figure. Calculate $\theta$. Take g $g=10\,m{{s}^{-2}}$. A) $45{}^\circ$            B) $60{}^\circ$                   C) $30{}^\circ$                  D)        $75{}^\circ$

[a] From graph, ${{u}_{y}}=10m/s$ ${{\text{v}}_{y}}$ becomes zero when $x=\frac{Range}{2}$ $\therefore$ Range $=20\text{ }m$ $\therefore \,\,\,\,\,\frac{2{{u}_{x}}{{u}_{y}}}{g}=20$