Q. It was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation $\frac{5\pi}{36}$ rad should strike a given target. In actual practice, it was found that a hill just prevented the trajectory. At what angle of elevation should the gun be to hit the target?
A) $\frac{5\pi}{36}rad$
B) $\frac{11\pi}{36}rad$
C) $\frac{7\pi}{36}rad$
D) $\frac{13\pi}{36}rad$
Explanation
(d) Required angle $= \frac{\pi}{2} - \frac{5\pi}{36} = \frac{18\pi - 5\pi}{36} = \frac{13\pi}{36}\ rad$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.