question_answer

Two projectiles A and B are projectiles with velocities \[\sqrt{2\upsilon }\]and \[\upsilon \] respectively. They have the same range. If A is thrown at angle of \[\mathbf{15}{}^\circ \] with the horizontal, then what is the angle of projection of B?

Answer:

                Given    \[{{R}_{A}}={{R}_{B}}\]                 or            \[\frac{{{(\sqrt{2\upsilon })}^{2}}\sin (2\times {{15}^{\circ }})}{g}=\frac{{{\upsilon }^{2}}\sin 2\theta }{g}\]                 or            \[\sin 2\theta =1=\sin {{90}^{\circ }}\]                                 \[\theta ={{45}^{\circ }}\]