Question

It was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation 5pi/36 rad should strike a given target in the same horizontal plane. In actual practice, it was found that a hill just prevented the trajectory. At what angle of elevation should the gun be fired to hit the target.

Answer 1

As per question, A hill just prevented the trajectory. In this case a shell should be fired at angle (π/2−θ ), so that it can hit the target. Thus, the required angle of elevation is given as,