question_answer

A projectile is fired at an angle of \[\mathbf{15}{}^\circ \] to the horizontal with the speed \[\upsilon \]. If another projectile is projected with the same speed, then at what angle with the horizontal it must be projected so as to have the same range?

Answer:

                For same R and \[\upsilon \], the sum of the two angles of projection is \[\text{9}0{}^\circ \]. As one angle is of\[\text{15}{}^\circ \], other should be\[\text{9}0{}^\circ -\text{15}{}^\circ \text{ }=\mathbf{75{}^\circ }\].