Question

it was calculated that a shell when fired from a gun with a certain velocity and at an angle of elevation 5pie/36

Answer 1

The angle of elevation is found to be 5π/36radians when a shell is fired from a gun at a certain velocity to strike a given target.

There was a hill that prevented the trajectory.

Therefore, the angle of elevation required for the gun to hit the target should be π/2 - 5π/36 = (18π-5π)/36 radians = 13π/36 radians.

So, the required angle of elevation for the gun to be fired is 13π/36.

Answer 2

During first projection, angle is 5π/36 with the horizontal.

But the hill is prevented the path.

Then the second projection having the angle π/2 -5π/36 with the horizontal.

Angle is 13π/36