question_answer 37)

                  The horizontal range of a projectile fired at an angle of \[{{15}^{o}}\] is 50 m. If it is fired with the same speed at an angle of \[{{45}^{o}}\], its range will be                 (a) 60 m                                (b) 71 m                 (c) 100 m                              (d) 141 in

Answer:

                  (c) \[\frac{{{R}_{2}}}{{{R}_{1}}}\,=\,\frac{\sin \,2{{\theta }_{2}}}{\sin \,2{{\theta }_{1}}}\,=\,\frac{\sin \,{{90}^{o}}}{\sin \,{{30}^{o}}}\,\,=\,\frac{1}{1/2}\,=2\]                 \[\therefore \]\[{{R}_{2}}=2{{R}_{1}}=\,2\times \,50\,=100\,\,m\].