A wall OP is inclined to the horizontal ground at an angle `alpha`. Two particles are projected from points A and B on the ground with same speed (u) in directions making an angle `theta` to the horizontal (see figure). Distance between points A and B is `x_(0) = 24 m`. Both particles hit the wall elastically and fall back on the ground. Time of flight (time required to hit the wall and then fall back on to the ground) for particles projected from A and B are 4 s and 2 s respectively. Both the particles strike the wall perpendicularly and at the same location. [In elastic collision, the velocity component of the particle that is perpendicular to the wall gets reversed without change in magnitude]
(a) Calculate maximum height attained by the particle projected from A.

(b) Calculate the inclination of the wall to the horizontal `(alpha) [g =10 m//s^(2)]`

Answer

(a) `11.25 m` (b) `tan^(-) ((8)/(5))`